diff --git a/.codecov.yml b/.codecov.yml
index b012da1..f7cb59e 100644
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -29,6 +29,6 @@
     changes: off
     patch:
       default:
-        threshold: 5
+        informational: true
 
 comment: false
diff --git a/.travis.yml b/.travis.yml
index d527954..2efa367 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,7 +21,13 @@
     - d: gdc
   include:
     - stage: test
-      d: dmd-2.078.0
+      d: dmd-2.081.1
+      env: [FRONTEND=2.081]
+    - d: dmd-2.080.1
+      env: [FRONTEND=2.080]
+    - d: dmd-2.079.1
+      env: [FRONTEND=2.078]
+    - d: dmd-2.078.1
       env: [FRONTEND=2.078]
     - d: dmd-2.077.1
       env: [FRONTEND=2.077, COVERAGE=true]
@@ -35,14 +41,12 @@
       env: [FRONTEND=2.073]
     - d: dmd-2.072.2
       env: [FRONTEND=2.072]
-    - d: dmd-2.071.2
-      env: [FRONTEND=2.071]
-    - d: dmd-2.070.2
-      env: [FRONTEND=2.070]
-    - d: dmd-2.069.2
-      env: [FRONTEND=2.069]
-    - d: dmd-2.068.2
-      env: [FRONTEND=2.068]
+    - d: ldc-1.10.0
+      env: [FRONTEND=2.080]
+    - d: ldc-1.9.0
+      env: [FRONTEND=2.079]
+    - d: ldc-1.8.0
+      env: [FRONTEND=2.078]
     - d: ldc-1.7.0
       env: [FRONTEND=2.077]
     - d: ldc-1.6.0
@@ -53,16 +57,6 @@
       env: [FRONTEND=2.074]
     - d: ldc-1.3.0
       env: [FRONTEND=2.073]
-    - d: ldc-1.2.0
-      env: [FRONTEND=2.072]
-    - d: ldc-1.1.0
-      env: [FRONTEND=2.071]
-    - d: ldc-1.0.0
-      env: [FRONTEND=2.070]
-    - d: gdc
-      env: [FRONTEND=2.068]
-    - d: gdc-4.8.5
-      env: [FRONTEND=2.068]
     - stage: deploy
       d: ldc
       os: osx
@@ -115,6 +109,6 @@
     if: type = pull_request or (type = push and branch = master)
   # Until deployment of the release binaries is fixed, always build them
   #- name: deploy
-    #if: type = push and tag =~ ^v
+    #if: type = push and tag =~ ^v\d+\.\d+\.\d+[^-]*\$ # not a pre-release tag
   - name: update-latest
-    if: type = push and tag =~ ^v
+    if: type = push and tag =~ ^v\d+\.\d+\.\d+[^-]*\$ # not a pre-release tag
diff --git a/changelog/buildSettingsVars.dd b/changelog/buildSettingsVars.dd
new file mode 100644
index 0000000..9e82917
--- /dev/null
+++ b/changelog/buildSettingsVars.dd
@@ -0,0 +1,21 @@
+Variables such as `$ARCH` or `$PLATFORM` are now supported in the build settings.
+
+JSON lines such as
+-------
+    "lflags-posix-x86": [ "-L$PACKAGE_DIR/lib/posix-x86" ],
+    "lflags-posix-x86_64": [ "-L$PACKAGE_DIR/lib/posix-x86_64" ],
+-------
+can be turned into
+-------
+    "lflags-posix": [ "-L$PACKAGE_DIR/lib/posix-$ARCH" ],
+-------
+
+Both `$VAR` and `${VAR}` syntaxes are supported.
+The supported variables are as follow:
+$(TABLE
+    $(TR $(TH name) $(TH values))
+    $(TR $(TD `$ARCH`) $(TD $(D_INLINECODE "x86", "x86_64")))
+    $(TR $(TD `$PLATFORM`) $(TD $(D_INLINECODE "linux", "windows", ...)))
+    $(TR $(TD `$PLATFORM_POSIX`) $(TD $(D_INLINECODE "posix", "windows", ...)))
+    $(TR $(TD `$BUILD_TYPE`) $(TD $(D_INLINECODE "debug", "release", ...)))
+)
diff --git a/changelog/buildTypeSyntax.dd b/changelog/buildTypeSyntax.dd
new file mode 100644
index 0000000..1afaa67
--- /dev/null
+++ b/changelog/buildTypeSyntax.dd
@@ -0,0 +1,3 @@
+DUB supports build type "syntax" 
+
+With this release new build type "syntax" is added. This build type is useful for IDEs to check the syntax of D coding without generating binaries.
\ No newline at end of file
diff --git a/changelog/env-var-replacement.dd b/changelog/env-var-replacement.dd
new file mode 100644
index 0000000..3fb9f55
--- /dev/null
+++ b/changelog/env-var-replacement.dd
@@ -0,0 +1,8 @@
+Enviroment variable expansion was improved
+
+Environment variable expansion now supports the braced `${MY_VAR}` expansion syntax: e.g. for `${PACKAGE_PATH}_suffix`.
+
+Moreover, `$PACKAGE_PATH`, `$ROOT_PACKAGE_PATH`, and `$DEP_PACKAGE_PATH` no longer end
+  with a `/` or `\` to support clean concatenation, e.g. `${PACKAGE_PATH}/subpath`.
+
+Learn more about the details at $(LINK2 https://github.com/dlang/dub/pull/1392, #1392).
diff --git a/changelog/recursive_dependecy_resolution.dd b/changelog/recursive_dependecy_resolution.dd
new file mode 100644
index 0000000..b8aa7fa
--- /dev/null
+++ b/changelog/recursive_dependecy_resolution.dd
@@ -0,0 +1,10 @@
+Dependency resolution has been reimplemented using a recursive algorithm
+
+The new algorithm minimizes the search space while descending the dependency
+graph. Compared to the old approach, it is now much less likely to run into
+pathological cases that result in exponential run time ("The dependency
+resolution algorithm is taking too long").
+
+Furthermore, the error message in case of unsatisfiable dependencies is more
+precise, usually making it straight forward to debug issues in the dependency
+graph of a failing package.
diff --git a/changelog/stdinForSingleFilePackages.dd b/changelog/stdinForSingleFilePackages.dd
new file mode 100644
index 0000000..a9f4b57
--- /dev/null
+++ b/changelog/stdinForSingleFilePackages.dd
@@ -0,0 +1,6 @@
+DUB accepts single file packages on STDIN
+
+You can pass single file packages to dub on STDIN using dash as first argument to DUB.
+All arguments after dash will be passed as runtime arguments to the application.
+
+Example `cat app.d | dub - --foo=bar`
\ No newline at end of file
diff --git a/changelog/upgrade_check.dd b/changelog/upgrade_check.dd
new file mode 100644
index 0000000..6b59134
--- /dev/null
+++ b/changelog/upgrade_check.dd
@@ -0,0 +1,8 @@
+The regular upgrade check has been removed
+
+Previously dub would regularly (once a day) check for possible package upgrades before building a packages.
+This lead to unexpected build failures, e.g. when internet connectivity was down or dependency resolution failed, and caused unnecessary delays.
+
+The build flag `--nodeps` now only suppresses resolution of missing dependencies.
+
+The new upgrade flag `--dry-run` was added to explicitly check for upgradable packages without actually upgrading anything.
diff --git a/dub.selections.json b/dub.selections.json
index 52e7c92..486c146 100644
--- a/dub.selections.json
+++ b/dub.selections.json
@@ -10,7 +10,7 @@
 		"libevent": "2.0.2+2.0.16",
 		"memutils": "0.4.9",
 		"openssl": "1.1.6+1.0.1g",
-		"stdx-allocator": "2.77.0",
+		"stdx-allocator": "2.77.2",
 		"taggedalgebraic": "0.10.8",
 		"vibe-core": "1.4.0-alpha.1",
 		"vibe-d": "0.8.3-alpha.3"
diff --git a/scripts/fish-completion/dub.fish b/scripts/fish-completion/dub.fish
index f55f345..c8cd222 100644
--- a/scripts/fish-completion/dub.fish
+++ b/scripts/fish-completion/dub.fish
@@ -49,7 +49,7 @@
 	complete -c dub -n "contains '$cmd' (commandline -poc)" -s a -l arch               -r -d "Force architecture"
 	complete -c dub -n "contains '$cmd' (commandline -poc)" -s d -l debug              -r -d "Debug identifier"
 	complete -c dub -n "contains '$cmd' (commandline -poc)"      -l nodeps                -d "No dependency check"
-	complete -c dub -n "contains '$cmd' (commandline -poc)" -s b -l build           -u -x -d "Build type"                        -a "debug plain release release-debug release-nobounds unittest profile profile-gc docs ddox cov unittest-cov"
+	complete -c dub -n "contains '$cmd' (commandline -poc)" -s b -l build           -u -x -d "Build type"                        -a "debug plain release release-debug release-nobounds unittest profile profile-gc docs ddox cov unittest-cov syntax"
 	complete -c dub -n "contains '$cmd' (commandline -poc)"      -l build-mode         -x -d "How compiler & linker are invoked" -a "separate allAtOnce singleFile"
 	complete -c dub -n "contains '$cmd' (commandline -poc)"      -l compiler           -x -d "Compiler binary"                   -a "dmd gdc ldc gdmd ldmd"
 end
diff --git a/semaphore-ci.sh b/semaphore-ci.sh
new file mode 100755
index 0000000..a415466
--- /dev/null
+++ b/semaphore-ci.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+set -euo pipefail
+set -x
+
+if  [ "${D_VERSION:-dmd}" == "gdc" ] ; then
+
+    # Use the dub-updating fork of the installer script until https://github.com/dlang/installer/pull/301 is merged
+    wget https://raw.githubusercontent.com/wilzbach/installer-dub/master/script/install.sh -O install.dub.sh
+    bash install.dub.sh -a dub
+    dub_path_activate="$(find $HOME/dlang/*/activate | head -1)"
+    rm "${dub_path_activate}"
+    dub_path="$(dirname "$dub_path_activate")"
+    sudo ln -s "${dub_path}/dub" /usr/bin/dub
+
+    export DMD=gdmd
+    export DC=gdc
+    # It's technically ~"2.076", but Ternary doesn't seem to have been ported and Vibe.d seems to depend on this.
+    # Ternary was added in 2.072: https://dlang.org/phobos/std_typecons.html#.Ternary
+    # However, the nonet tests is done only for > 2.072
+    export FRONTEND=2.072
+
+    sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+    sudo apt-get update
+    sudo apt-get install -y gdc-8
+    # fetch the dmd-like wrapper
+    sudo wget https://raw.githubusercontent.com/D-Programming-GDC/GDMD/master/dmd-script -O /usr/bin/gdmd
+    sudo chmod +x /usr/bin/gdmd
+    # DUB requires gdmd
+    sudo ln -s /usr/bin/gdc-8 /usr/bin/gdc
+    # fake install script and create a fake 'activate' script
+    mkdir -p ~/dlang/gdc-8
+    echo "deactivate(){ echo;}" > ~/dlang/gdc-8/activate
+
+else
+    curl --connect-timeout 5 --max-time 10 --retry 5 --retry-delay 1 --retry-max-time 60 https://dlang.org/install.sh | bash -s "$D_VERSION"
+fi
+
+./travis-ci.sh
diff --git a/source/dub/commandline.d b/source/dub/commandline.d
index 6f545b0..bd947f4 100644
--- a/source/dub/commandline.d
+++ b/source/dub/commandline.d
@@ -97,6 +97,16 @@
 		environment["TEMP"] = environment["TEMP"].replace("/", "\\");
 	}
 
+	// special stdin syntax
+	if (args.length >= 2 && args[1] == "-")
+	{
+		import dub.internal.utils: getTempFile;
+
+		auto path = getTempFile("app", ".d");
+		stdin.byChunk(4096).joiner.toFile(path.toNativeString());
+		args = args[0] ~ [path.toNativeString()] ~ args[2..$];
+	}
+
 	// special single-file package shebang syntax
 	if (args.length >= 2 && args[1].endsWith(".d")) {
 		args = args[0] ~ ["run", "-q", "--temp-build", "--single", args[1], "--"] ~ args[2 ..$];
@@ -245,7 +255,7 @@
 			// make the CWD package available so that for example sub packages can reference their
 			// parent package.
 			try dub.packageManager.getOrLoadPackage(NativePath(options.root_path));
-			catch (Exception e) { logDiagnostic("No package found in current working directory."); }
+			catch (Exception e) { logDiagnostic("No valid package found in current working directory: %s", e.msg); }
 		}
 	}
 
@@ -280,7 +290,11 @@
 	{
 		args.getopt("h|help", &help, ["Display general or command specific help"]);
 		args.getopt("root", &root_path, ["Path to operate in instead of the current working dir"]);
-		args.getopt("registry", &registry_urls, ["Search the given DUB registry URL first when resolving dependencies. Can be specified multiple times."]);
+		args.getopt("registry", &registry_urls, [
+			"Search the given registry URL first when resolving dependencies. Can be specified multiple times. Available registry types:",
+			"  DUB: URL to DUB registry (default)",
+			"  Maven: URL to Maven repository + group id containing dub packages as artifacts. E.g. mvn+http://localhost:8040/maven/libs-release/dubpackages",
+			]);
 		args.getopt("skip-registry", &skipRegistry, [
 			"Sets a mode for skipping the search on certain package registry types:",
 			"  none: Search all configured or default registries (default)",
@@ -595,7 +609,7 @@
 		args.getopt("b|build", &m_buildType, [
 			"Specifies the type of build to perform. Note that setting the DFLAGS environment variable will override the build type with custom flags.",
 			"Possible names:",
-			"  debug (default), plain, release, release-debug, release-nobounds, unittest, profile, profile-gc, docs, ddox, cov, unittest-cov and custom types"
+			"  debug (default), plain, release, release-debug, release-nobounds, unittest, profile, profile-gc, docs, ddox, cov, unittest-cov, syntax and custom types"
 		]);
 		args.getopt("c|config", &m_buildConfig, [
 			"Builds the specified configuration. Configurations can be defined in dub.json"
@@ -616,7 +630,7 @@
 			"Define the specified debug version identifier when building - can be used multiple times"
 		]);
 		args.getopt("nodeps", &m_nodeps, [
-			"Do not check/update dependencies before building"
+			"Do not resolve missing dependencies before building"
 		]);
 		args.getopt("build-mode", &m_buildMode, [
 			"Specifies the way the compiler and linker are invoked. Valid values:",
@@ -656,8 +670,6 @@
 		}
 
 		if (!m_nodeps) {
-			// TODO: only upgrade(select) if necessary, only upgrade(upgrade) every now and then
-
 			// retrieve missing packages
 			dub.project.reinit();
 			if (!dub.project.hasAllDependencies) {
@@ -665,11 +677,6 @@
 				if (m_single) dub.upgrade(UpgradeOptions.select | UpgradeOptions.noSaveSelections);
 				else dub.upgrade(UpgradeOptions.select);
 			}
-
-			if (!m_single) {
-				logDiagnostic("Checking for upgrades.");
-				dub.upgrade(UpgradeOptions.upgrade|UpgradeOptions.printUpgradesOnly|UpgradeOptions.useCachedResult);
-			}
 		}
 
 		dub.project.validate();
@@ -1127,6 +1134,7 @@
 		bool m_forceRemove = false;
 		bool m_missingOnly = false;
 		bool m_verify = false;
+		bool m_dryRun = false;
 	}
 
 	this()
@@ -1151,6 +1159,9 @@
 		args.getopt("verify", &m_verify, [
 			"Updates the project and performs a build. If successful, rewrites the selected versions file <to be implemented>."
 		]);
+		args.getopt("dry-run", &m_dryRun, [
+			"Only print what would be upgraded, but don't actually upgrade anything."
+		]);
 		args.getopt("missing-only", &m_missingOnly, [
 			"Performs an upgrade only for dependencies that don't yet have a version selected. This is also done automatically before each build."
 		]);
@@ -1169,6 +1180,7 @@
 		auto options = UpgradeOptions.upgrade|UpgradeOptions.select;
 		if (m_missingOnly) options &= ~UpgradeOptions.upgrade;
 		if (m_prerelease) options |= UpgradeOptions.preRelease;
+		if (m_dryRun) options |= UpgradeOptions.dryRun;
 		dub.upgrade(options, free_args);
 		return 0;
 	}
diff --git a/source/dub/compilers/utils.d b/source/dub/compilers/utils.d
index 999a69e..6e57867 100644
--- a/source/dub/compilers/utils.d
+++ b/source/dub/compilers/utils.d
@@ -192,6 +192,7 @@
 		{[BuildOption.optimize], "Call DUB with --build=release"},
 		{[BuildOption.profile], "Call DUB with --build=profile"},
 		{[BuildOption.unittests], "Call DUB with --build=unittest"},
+		{[BuildOption.syntaxOnly], "Call DUB with --build=syntax"},
 		{[BuildOption.warnings, BuildOption.warningsAsErrors], "Use \"buildRequirements\" to control the warning level"},
 		{[BuildOption.ignoreDeprecations, BuildOption.deprecationWarnings, BuildOption.deprecationErrors], "Use \"buildRequirements\" to control the deprecation warning level"},
 		{[BuildOption.property], "This flag is deprecated and has no effect"}
diff --git a/source/dub/dependencyresolver.d b/source/dub/dependencyresolver.d
index 1662cd3..3b61758 100644
--- a/source/dub/dependencyresolver.d
+++ b/source/dub/dependencyresolver.d
@@ -1,7 +1,7 @@
 /**
 	Dependency configuration/version resolution algorithm.
 
-	Copyright: © 2014 rejectedsoftware e.K.
+	Copyright: © 2014-2018 Sönke Ludwig
 	License: Subject to the terms of the MIT license, as written in the included LICENSE.txt file.
 	Authors: Sönke Ludwig
 */
@@ -18,7 +18,23 @@
 import std.string : format, indexOf, lastIndexOf;
 
 
+/** Resolves dependency graph with multiple configurations per package.
+
+	The term "configuration" can mean any kind of alternative dependency
+	configuration of a package. In particular, it can mean different
+	versions of a package.
+
+	`CONFIG` is an abstract type denoting a single configuration of a certain
+	package, whereas `CONFIGS` denotes a set of configurations. The
+	representation of both can be freely chosen, so that `CONFIGS` for example
+	can be defined in terms of a version range.
+*/
 class DependencyResolver(CONFIGS, CONFIG) {
+	/** Encapsulates a list of outgoing edges in the dependency graph.
+
+		A value of this type represents a single dependency with multiple
+		possible configurations for the target package.
+	*/
 	static struct TreeNodes {
 		string pack;
 		CONFIGS configs;
@@ -37,6 +53,10 @@
 		}
 	}
 
+	/** A single node in the dependency graph.
+
+		Nodes are a combination of a package and a single package configuration.
+	*/
 	static struct TreeNode {
 		string pack;
 		CONFIG config;
@@ -54,230 +74,33 @@
 		}
 	}
 
-	private static struct PackageConfigs
-	{
-		static struct Depender
-		{
-			TreeNode origin;
-			TreeNodes dependency;
-		}
-
-		// all possible configurations to test for this package
-		CONFIG[] allConfigs;
-
-		// determines whether this package has any dependencies, may be
-		// different from allConfigs.length > 0 after certain configurations
-		// have been filtered out
-		bool anyConfig;
-
-		Depender[] origins;
-	}
-
 	CONFIG[string] resolve(TreeNode root, bool throw_on_failure = true)
 	{
-		auto root_base_pack = basePackage(root.pack);
-
-		// find all possible configurations of each possible dependency
-		size_t[string] package_indices;
-		string[size_t] package_names;
-		PackageConfigs[] configs;
-		bool[string] maybe_optional_deps;
-		bool[TreeNode] visited;
-
-		void findConfigsRec(TreeNode parent, bool parent_unique)
-		{
-			if (parent in visited) return;
-			visited[parent] = true;
-
-			foreach (ch; getChildren(parent)) {
-				auto basepack = basePackage(ch.pack);
-				auto pidx = configs.length;
-
-				if (ch.depType != DependencyType.required) maybe_optional_deps[ch.pack] = true;
-
-				PackageConfigs config;
-				if (auto pi = basepack in package_indices) {
-					pidx = *pi;
-					config = configs[*pi];
-				} else {
-					if (basepack == root_base_pack) config.allConfigs = [root.config];
-					else config.allConfigs = getAllConfigs(basepack);
-					configs ~= config;
-					package_indices[basepack] = pidx;
-					package_names[pidx] = basepack;
-				}
-
-				foreach (c; getSpecificConfigs(basepack, ch))
-					if (!config.allConfigs.canFind(c))
-						config.allConfigs = c ~ config.allConfigs;
-
-				if (config.allConfigs.length > 0)
-					config.anyConfig = true;
-
-				// store package depending on this for better error messages
-				config.origins ~= PackageConfigs.Depender(parent, ch);
-
-				// eliminate configurations from which we know that they can't satisfy
-				// the uniquely defined root dependencies (==version or ~branch style dependencies)
-				if (parent_unique) config.allConfigs = config.allConfigs.filter!(c => matches(ch.configs, c)).array;
-
-				configs[pidx] = config;
-
-				foreach (v; config.allConfigs)
-					findConfigsRec(TreeNode(ch.pack, v), parent_unique && config.allConfigs.length == 1);
-			}
-		}
-		findConfigsRec(root, true);
-
-		// append an invalid configuration to denote an unchosen dependency
-		// this is used to properly support optional dependencies (when
-		// getChildren() returns no configurations for an optional dependency,
-		// but getAllConfigs() has already provided an existing list of configs)
-		foreach (i, ref cfgs; configs)
-			if (cfgs.allConfigs.length == 0 || package_names[i] in maybe_optional_deps)
-				cfgs.allConfigs = cfgs.allConfigs ~ CONFIG.invalid;
-
-		logDebug("Configurations used for dependency resolution:");
-		foreach (n, i; package_indices) logDebug("  %s (%s%s): %s", n, i, n in maybe_optional_deps ? ", maybe optional" : ", required", configs[i]);
-
-		auto config_indices = new size_t[configs.length];
-		config_indices[] = 0;
-
-		visited = null;
-		sizediff_t validateConfigs(TreeNode parent, ref ConflictError error)
-		{
-			import std.algorithm : max;
-
-			if (parent in visited) return -1;
-
-			visited[parent] = true;
-			sizediff_t maxcpi = -1;
-			sizediff_t parentidx = package_indices.get(basePackage(parent.pack), -1);
-			auto parentbase = basePackage(parent.pack);
-
-			// loop over all dependencies
-			foreach (ch; getChildren(parent)) {
-				auto basepack = basePackage(ch.pack);
-				assert(basepack in package_indices, format("%s not in packages %s", basepack, package_indices));
-
-				// get the current config/version of the current dependency
-				sizediff_t childidx = package_indices[basepack];
-				auto child = configs[childidx];
-
-				if (child.allConfigs.length == 1 && child.allConfigs[0] == CONFIG.invalid) {
-					// ignore invalid optional dependencies
-					if (ch.depType != DependencyType.required)
-						continue;
-
-					if (parentbase == root_base_pack) {
-						import std.uni : toLower;
-						auto lp = ch.pack.toLower();
-						if (lp != ch.pack) {
-							logError("Dependency \"%s\" of %s contains upper case letters, but must be lower case.", ch.pack, parent.pack);
-							if (getAllConfigs(lp).length) logError("Did you mean \"%s\"?", lp);
-						}
-						if (child.anyConfig)
-							throw new Exception(format("Root package %s reference %s %s cannot be satisfied.\nPackages causing the conflict:\n\t%s",
-								parent.pack, ch.pack, ch.configs,
-								child.origins.map!(a => a.origin.pack ~ " depends on " ~ a.dependency.configs.to!string).join("\n\t")));
-						else
-							throw new Exception(format("Root package %s references unknown package %s", parent.pack, ch.pack));
-					}
-					// choose another parent config to avoid the invalid child
-					if (parentidx > maxcpi) {
-						error = ConflictError(ConflictError.Kind.invalidDependency, parent, ch, CONFIG.invalid);
-						logDiagnostic("%s (ci=%s)", error, parentidx);
-						maxcpi = parentidx;
-					}
-				} else {
-					auto config = child.allConfigs[config_indices[childidx]];
-					auto chnode = TreeNode(ch.pack, config);
-
-					if (config == CONFIG.invalid || !matches(ch.configs, config)) {
-						// ignore missing optional dependencies
-						if (config == CONFIG.invalid && ch.depType != DependencyType.required)
-							continue;
-
-						// if we are at the root level, we can safely skip the maxcpi computation and instead choose another childidx config
-						if (parentbase == root_base_pack) {
-							error = ConflictError(ConflictError.Kind.noRootMatch, parent, ch, config);
-							return childidx;
-						}
-
-						if (childidx > maxcpi) {
-							maxcpi = max(childidx, parentidx);
-							error = ConflictError(ConflictError.Kind.childMismatch, parent, ch, config);
-							logDebug("%s (ci=%s)", error, maxcpi);
-						}
-
-						// we know that either the child or the parent needs to be switched
-						// to another configuration, no need to continue with other children
-						if (config == CONFIG.invalid) break;
-					}
-
-					maxcpi = max(maxcpi, validateConfigs(chnode, error));
-				}
-			}
-			return maxcpi;
-		}
-
-		Nullable!ConflictError first_error;
-		size_t loop_counter = 0;
-
 		// Leave the possibility to opt-out from the loop limit
 		import std.process : environment;
 		bool no_loop_limit = environment.get("DUB_NO_RESOLVE_LIMIT") !is null;
 
-		while (true) {
-			assert(no_loop_limit || loop_counter++ < 1_000_000,
-				"The dependency resolution process is taking too long. The"
-				~ " dependency graph is likely hitting a pathological case in"
-				~ " the resolution algorithm. Please file a bug report at"
-				~ " https://github.com/dlang/dub/issues and mention the package"
-				~ " recipe that reproduces this error.");
+		auto rootbase = root.pack.basePackageName;
 
-			// check if the current combination of configurations works out
-			visited = null;
-			ConflictError error;
-			auto conflict_index = validateConfigs(root, error);
-			if (first_error.isNull) first_error = error;
+		// build up the dependency graph, eliminating as many configurations/
+		// versions as possible
+		ResolveContext context;
+		context.configs[rootbase] = [ResolveConfig(root.config, true)];
+		long loop_counter = no_loop_limit ? long.max : 1_000_000;
+		constrain(root, context, loop_counter);
 
-			// print out current iteration state
-			logDebug("Interation (ci=%s) %s", conflict_index, {
-				import std.array : join;
-				auto cs = new string[configs.length];
-				foreach (p, i; package_indices) {
-					if (configs[i].allConfigs.length)
-						cs[i] = p~" "~configs[i].allConfigs[config_indices[i]].to!string~(i >= 0 && i >= conflict_index ? " (C)" : "");
-					else cs[i] = p ~ " [no config]";
-				}
-				return cs.join(", ");
-			}());
+		// remove any non-default optional dependencies
+		purgeOptionalDependencies(root, context.result);
 
-			if (conflict_index < 0) {
-				CONFIG[string] ret;
-				foreach (p, i; package_indices)
-					if (configs[i].allConfigs.length) {
-						auto cfg = configs[i].allConfigs[config_indices[i]];
-						if (cfg != CONFIG.invalid) ret[p] = cfg;
-					}
-				logDebug("Resolved dependencies before optional-purge: %s", ret.byKey.map!(k => k~" "~ret[k].to!string));
-				purgeOptionalDependencies(root, ret);
-				logDebug("Resolved dependencies after optional-purge: %s", ret.byKey.map!(k => k~" "~ret[k].to!string));
-				return ret;
-			}
+		// the root package is implied by the `root` argument and will not be
+		// returned explicitly
+		context.result.remove(rootbase);
 
-			// find the next combination of configurations
-			foreach_reverse (pi, ref i; config_indices) {
-				if (pi > conflict_index) i = 0;
-				else if (++i >= configs[pi].allConfigs.length) i = 0;
-				else break;
-			}
-			if (config_indices.all!"a==0") {
-				if (throw_on_failure) throw new Exception(format("Could not find a valid dependency tree configuration: %s", first_error.get));
-				else return null;
-			}
-		}
+		logDiagnostic("Dependency resolution result:");
+		foreach (d; context.result.keys.sort())
+			logDiagnostic("  %s: %s", d, context.result[d]);
+
+		return context.result;
 	}
 
 	protected abstract CONFIG[] getAllConfigs(string pack);
@@ -285,6 +108,154 @@
 	protected abstract TreeNodes[] getChildren(TreeNode node);
 	protected abstract bool matches(CONFIGS configs, CONFIG config);
 
+	private static struct ResolveConfig {
+		CONFIG config;
+		bool included;
+	}
+
+	private static struct ResolveContext {
+		/** Contains all packages visited by the resolution process so far.
+
+			The key is the qualified name of the package (base + sub)
+		*/
+		void[0][string] visited;
+
+		/// The finally chosen configurations for each package
+		CONFIG[string] result;
+
+		/// The set of available configurations for each package
+		ResolveConfig[][string] configs;
+
+		/// Determines if a certain package has already been processed
+		bool isVisited(string package_) const { return (package_ in visited) !is null; }
+
+		/// Marks a package as processed
+		void setVisited(string package_) { visited[package_] = (void[0]).init; }
+
+		/// Returns a deep clone
+		ResolveContext clone()
+		{
+			ResolveContext ret;
+			ret.visited = this.visited.dup;
+			ret.result = this.result.dup;
+			foreach (pack, cfgs; this.configs) {
+				ret.configs[pack] = cfgs.dup;
+			}
+			return ret;
+		}
+	}
+
+
+	/** Starting with a single node, fills `context` with a minimized set of
+		configurations that form valid solutions.
+	*/
+	private void constrain(TreeNode n, ref ResolveContext context, ref long max_iterations)
+	{
+		auto base = n.pack.basePackageName;
+		assert(base in context.configs);
+		if (context.isVisited(n.pack)) return;
+		context.setVisited(n.pack);
+		context.result[base] = n.config;
+		foreach (j, ref sc; context.configs[base])
+			sc.included = sc.config == n.config;
+
+		auto dependencies = getChildren(n);
+
+		foreach (dep; dependencies) {
+			// lazily load all dependency configurations
+			auto depbase = dep.pack.basePackageName;
+			auto di = depbase in context.configs;
+			if (!di) {
+				context.configs[depbase] =
+					getAllConfigs(depbase)
+					.map!(c => ResolveConfig(c, true))
+					.array;
+				di = depbase in context.configs;
+			}
+
+			// add any dependee defined dependency configurations
+			foreach (sc; getSpecificConfigs(n.pack, dep))
+				if (!(*di).canFind!(c => c.config == sc))
+					*di = ResolveConfig(sc, true) ~ *di;
+
+			// restrain the configurations to the current dependency spec
+			bool any_config = false;
+			foreach (i, ref c; *di)
+				if (c.included) {
+					if (!matches(dep.configs, c.config))
+						c.included = false;
+					else any_config = true;
+				}
+
+			if (!any_config && dep.depType == DependencyType.required) {
+				if ((*di).length)
+					throw new ResolveException(n, dep, context);
+				else throw new DependencyLoadException(n, dep);
+			}
+		}
+
+		constrainDependencies(n, dependencies, 0, context, max_iterations);
+	}
+
+	/** Recurses back into `constrain` while recursively going through `n`'s
+		dependencies.
+
+		This attempts to constrain each dependency, while keeping each of them
+		in a nested stack frame. This allows any errors to properly back
+		propagate.
+	*/
+	private void constrainDependencies(TreeNode n, TreeNodes[] dependencies, size_t depidx,
+		ref ResolveContext context, ref long max_iterations)
+	{
+		if (depidx >= dependencies.length) return;
+
+		assert (--max_iterations > 0,
+			"The dependency resolution process is taking too long. The"
+			~ " dependency graph is likely hitting a pathological case in"
+			~ " the resolution algorithm. Please file a bug report at"
+			~ " https://github.com/dlang/dub/issues and mention the package"
+			~ " recipe that reproduces this error.");
+
+		auto dep = &dependencies[depidx];
+		auto depbase = dep.pack.basePackageName;
+		auto depconfigs = context.configs[depbase];
+
+		Exception first_err;
+
+		// try each configuration/version of the current dependency
+		foreach (i, c; depconfigs) {
+			if (c.included) {
+				try {
+					// try the configuration on a cloned context
+					auto subcontext = context.clone;
+					constrain(TreeNode(dep.pack, c.config), subcontext, max_iterations);
+					constrainDependencies(n, dependencies, depidx+1, subcontext, max_iterations);
+					// if a branch succeeded, replace the current context
+					// with the one from the branch and return
+					context = subcontext;
+					return;
+				} catch (Exception e) {
+					if (!first_err) first_err = e;
+				}
+			}
+		}
+
+		// ignore unsatisfiable optional dependencies
+		if (dep.depType != DependencyType.required) {
+			auto subcontext = context.clone;
+			constrainDependencies(n, dependencies, depidx+1, subcontext, max_iterations);
+			context = subcontext;
+			return;
+		}
+
+		// report the first error encountered to the user
+		if (first_err) throw first_err;
+
+		// should have thrown in constrainRec before reaching this
+		assert(false, format("Got no configuration for dependency %s %s of %s %s!?",
+			dep.pack, dep.configs, n.pack, n.config));
+	}
+
 	private void purgeOptionalDependencies(TreeNode root, ref CONFIG[string] configs)
 	{
 		bool[string] required;
@@ -294,9 +265,9 @@
 		{
 			if (node.pack in visited) return;
 			visited[node.pack] = true;
-			required[basePackage(node.pack)] = true;
+			required[node.pack.basePackageName] = true;
 			foreach (dep; getChildren(node).filter!(dep => dep.depType != DependencyType.optional))
-				if (auto dp = basePackage(dep.pack) in configs)
+				if (auto dp = dep.pack.basePackageName in configs)
 					markRecursively(TreeNode(dep.pack, *dp));
 		}
 
@@ -309,35 +280,56 @@
 				configs.remove(p);
 	}
 
-	private struct ConflictError {
-		enum Kind {
-			none,
-			noRootMatch,
-			childMismatch,
-			invalidDependency
-		}
+	final class ResolveException : Exception {
+		import std.range : chain, only;
+		import std.typecons : tuple;
 
-		Kind kind;
-		TreeNode parent;
-		TreeNodes child;
-		CONFIG config;
+		string failedNode;
 
-		string toString()
-		const {
-			final switch (kind) {
-				case Kind.none: return "no error";
-				case Kind.noRootMatch:
-					return "No match for dependency %s %s of %s"
-						.format(child.pack, child.configs, parent.pack);
-				case Kind.childMismatch:
-					return "Dependency %s -> %s %s mismatches with selected version %s"
-						.format(parent.pack, child.pack, child.configs, config);
-				case Kind.invalidDependency:
-					return "Package %s contains invalid dependency %s (no version candidates)"
-						.format(parent.pack, child.pack);
+		this(TreeNode parent, TreeNodes dep, in ref ResolveContext context, string file = __FILE__, size_t line = __LINE__)
+		{
+			auto m = format("Unresolvable dependencies to package %s:", dep.pack.basePackageName);
+			super(m, file, line);
+
+			this.failedNode = dep.pack;
+
+			auto failbase = failedNode.basePackageName;
+
+			// get the list of all dependencies to the failed package
+			auto deps = context.visited.byKey
+				.filter!(p => p.basePackageName in context.result)
+				.map!(p => TreeNode(p, context.result[p.basePackageName]))
+				.map!(n => getChildren(n)
+					.filter!(d => d.pack.basePackageName == failbase)
+					.map!(d => tuple(n, d))
+				)
+				.join
+				.sort!((a, b) => a[0].pack < b[0].pack);
+
+			foreach (d; deps) {
+				// filter out trivial self-dependencies
+				if (d[0].pack.basePackageName == failbase
+					&& matches(d[1].configs, d[0].config))
+					continue;
+				msg ~= format("\n  %s %s depends on %s %s", d[0].pack, d[0].config, d[1].pack, d[1].configs);
 			}
 		}
 	}
+
+	final class DependencyLoadException : Exception {
+		TreeNode parent;
+		TreeNodes dependency;
+
+		this(TreeNode parent, TreeNodes dep)
+		{
+			auto m = format("Failed to find any versions for package %s, referenced by %s %s",
+				dep.pack, parent.pack, parent.config);
+			super(m, file, line);
+
+			this.parent = parent;
+			this.dependency = dep;
+		}
+	}
 }
 
 enum DependencyType {
@@ -346,14 +338,12 @@
 	optional
 }
 
-private string basePackage(string p)
+private string basePackageName(string p)
 {
-	auto idx = indexOf(p, ':');
-	if (idx < 0) return p;
-	return p[0 .. idx];
+	import std.algorithm.searching : findSplit;
+	return p.findSplit(":")[0];
 }
 
-
 unittest {
 	static struct IntConfig {
 		int value;
@@ -457,7 +447,7 @@
 		assert(res.resolve(TreeNode("a", ic(0))) == ["b":ic(2)], to!string(res.resolve(TreeNode("a", ic(0)))));
 	}
 
-	// make sure non-satisfyable dependencies are not a problem, even if non-optional in some dependencies
+	// make sure non-satisfiable dependencies are not a problem, even if non-optional in some dependencies
 	with (TestResolver) {
 		auto res = new TestResolver([
 			"a:0": [TreeNodes("b", ics([ic(1), ic(2)]))],
@@ -467,4 +457,50 @@
 		]);
 		assert(res.resolve(TreeNode("a", ic(0))) == ["b":ic(2)], to!string(res.resolve(TreeNode("a", ic(0)))));
 	}
+
+	// check error message for multiple conflicting dependencies
+	with (TestResolver) {
+		auto res = new TestResolver([
+			"a:0": [TreeNodes("b", ics([ic(1)])), TreeNodes("c", ics([ic(1)]))],
+			"b:1": [TreeNodes("d", ics([ic(1)]))],
+			"c:1": [TreeNodes("d", ics([ic(2)]))],
+			"d:1": [],
+			"d:2": []
+		]);
+		try {
+			res.resolve(TreeNode("a", ic(0)));
+			assert(false, "Expected resolve to throw.");
+		} catch (ResolveException e) {
+			assert(e.msg ==
+				"Unresolvable dependencies to package d:"
+				~ "\n  b 1 depends on d [1]"
+				~ "\n  c 1 depends on d [2]");
+		}
+	}
+
+	// check error message for invalid dependency
+	with (TestResolver) {
+		auto res = new TestResolver([
+			"a:0": [TreeNodes("b", ics([ic(1)]))]
+		]);
+		try {
+			res.resolve(TreeNode("a", ic(0)));
+			assert(false, "Expected resolve to throw.");
+		} catch (DependencyLoadException e) {
+			assert(e.msg == "Failed to find any versions for package b, referenced by a 0");
+		}
+	}
+
+	// regression: unresolvable optional dependency skips the remaining dependencies
+	with (TestResolver) {
+		auto res = new TestResolver([
+			"a:0": [
+				TreeNodes("b", ics([ic(2)]), DependencyType.optional),
+				TreeNodes("c", ics([ic(1)]))
+			],
+			"b:1": [],
+			"c:1": []
+		]);
+		assert(res.resolve(TreeNode("a", ic(0))) == ["c":ic(1)]);
+	}
 }
diff --git a/source/dub/dub.d b/source/dub/dub.d
index c6a79a5..544805f 100644
--- a/source/dub/dub.d
+++ b/source/dub/dub.d
@@ -167,6 +167,46 @@
 
 		init();
 
+		if (skip_registry == SkipPackageSuppliers.none)
+			m_packageSuppliers = getPackageSuppliers(additional_package_suppliers);
+		else
+			m_packageSuppliers = getPackageSuppliers(additional_package_suppliers, skip_registry);
+
+		m_packageManager = new PackageManager(m_dirs.localRepository, m_dirs.systemSettings);
+
+		auto ccps = m_config.customCachePaths;
+		if (ccps.length)
+			m_packageManager.customCachePaths = ccps;
+
+		updatePackageSearchPath();
+	}
+
+	unittest
+	{
+		scope (exit) environment.remove("DUB_REGISTRY");
+		auto dub = new Dub(".", null, SkipPackageSuppliers.configured);
+		assert(dub.m_packageSuppliers.length == 0);
+		environment["DUB_REGISTRY"] = "http://example.com/";
+		dub = new Dub(".", null, SkipPackageSuppliers.configured);
+		assert(dub.m_packageSuppliers.length == 1);
+		environment["DUB_REGISTRY"] = "http://example.com/;http://foo.com/";
+		dub = new Dub(".", null, SkipPackageSuppliers.configured);
+		assert(dub.m_packageSuppliers.length == 2);
+		dub = new Dub(".", [new RegistryPackageSupplier(URL("http://bar.com/"))], SkipPackageSuppliers.configured);
+		assert(dub.m_packageSuppliers.length == 3);
+	}
+
+	/** Get the list of package suppliers.
+
+		Params:
+			additional_package_suppliers = A list of package suppliers to try
+				before the suppliers found in the configurations files and the
+				`defaultPackageSuppliers`.
+			skip_registry = Can be used to skip using the configured package
+				suppliers, as well as the default suppliers.
+	*/
+	public PackageSupplier[] getPackageSuppliers(PackageSupplier[] additional_package_suppliers, SkipPackageSuppliers skip_registry)
+	{
 		PackageSupplier[] ps = additional_package_suppliers;
 
 		if (skip_registry < SkipPackageSuppliers.all)
@@ -187,30 +227,31 @@
 		if (skip_registry < SkipPackageSuppliers.standard)
 			ps ~= defaultPackageSuppliers();
 
-		m_packageSuppliers = ps;
-		m_packageManager = new PackageManager(m_dirs.localRepository, m_dirs.systemSettings);
+		return ps;
+	}
 
-		auto ccps = m_config.customCachePaths;
-		if (ccps.length)
-			m_packageManager.customCachePaths = ccps;
-
-		updatePackageSearchPath();
+	/// ditto
+	public PackageSupplier[] getPackageSuppliers(PackageSupplier[] additional_package_suppliers)
+	{
+		return getPackageSuppliers(additional_package_suppliers, m_config.skipRegistry);
 	}
 
 	unittest
 	{
 		scope (exit) environment.remove("DUB_REGISTRY");
-		auto dub = new Dub(".", null, SkipPackageSuppliers.configured);
-		assert(dub.m_packageSuppliers.length == 0);
+		auto dub = new Dub(".", null, SkipPackageSuppliers.none);
+
+		dub.m_config = new DubConfig(Json(["skipRegistry": Json("none")]), null);
+		assert(dub.getPackageSuppliers(null).length == 1);
+
+		dub.m_config = new DubConfig(Json(["skipRegistry": Json("configured")]), null);
+		assert(dub.getPackageSuppliers(null).length == 0);
+
+		dub.m_config = new DubConfig(Json(["skipRegistry": Json("standard")]), null);
+		assert(dub.getPackageSuppliers(null).length == 0);
+
 		environment["DUB_REGISTRY"] = "http://example.com/";
-		dub = new Dub(".", null, SkipPackageSuppliers.configured);
-		logInfo("%s", dub.m_packageSuppliers);
-		assert(dub.m_packageSuppliers.length == 1);
-		environment["DUB_REGISTRY"] = "http://example.com/;http://foo.com/";
-		dub = new Dub(".", null, SkipPackageSuppliers.configured);
-		assert(dub.m_packageSuppliers.length == 2);
-		dub = new Dub(".", [new RegistryPackageSupplier(URL("http://bar.com/"))], SkipPackageSuppliers.configured);
-		assert(dub.m_packageSuppliers.length == 3);
+		assert(dub.getPackageSuppliers(null).length == 1);
 	}
 
 	/** Initializes the instance with a single package search path, without
@@ -484,21 +525,12 @@
 		}
 
 		Dependency[string] versions;
-		if ((options & UpgradeOptions.useCachedResult) && m_project.isUpgradeCacheUpToDate() && !packages_to_upgrade.length) {
-			logDiagnostic("Using cached upgrade results...");
-			versions = m_project.getUpgradeCache();
-		} else {
-			auto resolver = new DependencyVersionResolver(this, options);
-			foreach (p; packages_to_upgrade)
-				resolver.addPackageToUpgrade(p);
-			versions = resolver.resolve(m_project.rootPackage, m_project.selections);
-			if (options & UpgradeOptions.useCachedResult) {
-				logDiagnostic("Caching upgrade results...");
-				m_project.setUpgradeCache(versions);
-			}
-		}
+		auto resolver = new DependencyVersionResolver(this, options);
+		foreach (p; packages_to_upgrade)
+			resolver.addPackageToUpgrade(p);
+		versions = resolver.resolve(m_project.rootPackage, m_project.selections);
 
-		if (options & UpgradeOptions.printUpgradesOnly) {
+		if (options & UpgradeOptions.dryRun) {
 			bool any = false;
 			string rootbasename = getBasePackageName(m_project.rootPackage.name);
 
@@ -509,7 +541,7 @@
 				if (basename == rootbasename) continue;
 
 				if (!m_project.selections.hasSelectedVersion(basename)) {
-					logInfo("Non-selected package %s is available with version %s.",
+					logInfo("Package %s would be selected with version %s.",
 						basename, ver);
 					any = true;
 					continue;
@@ -517,7 +549,7 @@
 				auto sver = m_project.selections.getSelectedVersion(basename);
 				if (!sver.path.empty) continue;
 				if (ver.version_ <= sver.version_) continue;
-				logInfo("Package %s can be upgraded from %s to %s.",
+				logInfo("Package %s would be upgraded from %s to %s.",
 					basename, sver, ver);
 				any = true;
 			}
@@ -562,7 +594,7 @@
 
 		m_project.reinit();
 
-		if ((options & UpgradeOptions.select) && !(options & UpgradeOptions.noSaveSelections))
+		if ((options & UpgradeOptions.select) && !(options & (UpgradeOptions.noSaveSelections | UpgradeOptions.dryRun)))
 			m_project.saveSelections();
 	}
 
@@ -601,7 +633,7 @@
 		auto test_config = format("%s-test-%s", m_project.rootPackage.name.replace(".", "-").replace(":", "-"), config);
 
 		BuildSettings lbuildsettings = settings.buildSettings;
-		m_project.addBuildSettings(lbuildsettings, settings.platform, config, null, true);
+		m_project.addBuildSettings(lbuildsettings, settings, config, null, true);
 		if (lbuildsettings.targetType == TargetType.none) {
 			logInfo(`Configuration '%s' has target type "none". Skipping test.`, config);
 			return;
@@ -1340,8 +1372,9 @@
 	preRelease = 1<<2, /// inclde pre-release versions in upgrade
 	forceRemove = 1<<3, /// Deprecated, does nothing.
 	select = 1<<4, /// Update the dub.selections.json file with the upgraded versions
-	printUpgradesOnly = 1<<5, /// Instead of downloading new packages, just print a message to notify the user of their existence
-	useCachedResult = 1<<6, /// Use cached information stored with the package to determine upgrades
+	dryRun = 1<<5, /// Instead of downloading new packages, just print a message to notify the user of their existence
+	/*deprecated*/ printUpgradesOnly = dryRun, /// deprecated, use dryRun instead
+	/*deprecated*/ useCachedResult = 1<<6, /// deprecated, has no effect
 	noSaveSelections = 1<<7, /// Don't store updated selections on disk
 }
 
@@ -1658,6 +1691,17 @@
 		return ret;
 	}
 
+	@property SkipPackageSuppliers skipRegistry()
+	{
+		if(auto pv = "skipRegistry" in m_data)
+			return to!SkipPackageSuppliers((*pv).get!string);
+
+		if (m_parentConfig)
+			return m_parentConfig.skipRegistry;
+
+		return SkipPackageSuppliers.none;
+	}
+
 	@property NativePath[] customCachePaths()
 	{
 		import std.algorithm.iteration : map;
diff --git a/source/dub/generators/generator.d b/source/dub/generators/generator.d
index 588a111..ef51351 100644
--- a/source/dub/generators/generator.d
+++ b/source/dub/generators/generator.d
@@ -95,7 +95,7 @@
 		foreach (pack; m_project.getTopologicalPackageList(true, null, configs)) {
 			BuildSettings buildSettings;
 			auto config = configs[pack.name];
-			buildSettings.processVars(m_project, pack, pack.getBuildSettings(settings.platform, config), true);
+			buildSettings.processVars(m_project, pack, pack.getBuildSettings(settings.platform, config), settings, true);
 			targets[pack.name] = TargetInfo(pack, [pack], config, buildSettings);
 
 			prepareGeneration(pack, m_project, settings, buildSettings);
@@ -112,7 +112,7 @@
 
 		foreach (pack; m_project.getTopologicalPackageList(true, null, configs)) {
 			BuildSettings buildsettings;
-			buildsettings.processVars(m_project, pack, pack.getBuildSettings(settings.platform, configs[pack.name]), true);
+			buildsettings.processVars(m_project, pack, pack.getBuildSettings(settings.platform, configs[pack.name]), settings, true);
 			bool generate_binary = !(buildsettings.options & BuildOption.syntaxOnly);
 			finalizeGeneration(pack, m_project, settings, buildsettings, NativePath(bs.targetPath), generate_binary);
 		}
@@ -412,13 +412,13 @@
 	}
 
 	// configure targets for build types such as release, or unittest-cov
-	private void addBuildTypeSettings(TargetInfo[string] targets, GeneratorSettings settings)
+	private void addBuildTypeSettings(TargetInfo[string] targets, in GeneratorSettings settings)
 	{
 		foreach (ref ti; targets.byValue) {
 			ti.buildSettings.add(settings.buildSettings);
 
 			// add build type settings and convert plain DFLAGS to build options
-			m_project.addBuildTypeSettings(ti.buildSettings, settings.platform, settings.buildType, ti.pack is m_project.rootPackage);
+			m_project.addBuildTypeSettings(ti.buildSettings, settings, ti.pack is m_project.rootPackage);
 			settings.compiler.extractBuildOptions(ti.buildSettings);
 
 			auto tt = ti.buildSettings.targetType;
diff --git a/source/dub/generators/sublimetext.d b/source/dub/generators/sublimetext.d
index 57a8012..9ac53c9 100644
--- a/source/dub/generators/sublimetext.d
+++ b/source/dub/generators/sublimetext.d
@@ -80,6 +80,7 @@
 		"profile-gc",
 		"cov",
 		"unittest-cov",
+		"syntax"
 		];
 
 	string fileRegex;
diff --git a/source/dub/internal/utils.d b/source/dub/internal/utils.d
index 4eb455a..3e36af7 100644
--- a/source/dub/internal/utils.d
+++ b/source/dub/internal/utils.d
@@ -40,8 +40,14 @@
 NativePath getTempFile(string prefix, string extension = null)
 {
 	import std.uuid : randomUUID;
+	import std.array: replace;
 
-	auto path = getTempDir() ~ (prefix ~ "-" ~ randomUUID.toString() ~ extension);
+	string fileName = prefix ~ "-" ~ randomUUID.toString() ~ extension;
+
+	if (extension !is null && extension == ".d")
+		fileName = fileName.replace("-", "_");
+
+	auto path = getTempDir() ~ fileName;
 	temporary_files ~= path;
 	return path;
 }
diff --git a/source/dub/internal/vibecompat/inet/url.d b/source/dub/internal/vibecompat/inet/url.d
index 6016af5..720d5d0 100644
--- a/source/dub/internal/vibecompat/inet/url.d
+++ b/source/dub/internal/vibecompat/inet/url.d
@@ -18,6 +18,7 @@
 import std.exception;
 import std.string;
 import std.uri;
+import std.meta : AliasSeq;
 
 
 /**
@@ -34,6 +35,7 @@
 		string m_password;
 		string m_queryString;
 		string m_anchor;
+		alias m_schemes = AliasSeq!("http", "https", "ftp", "spdy", "file", "sftp");
 	}
 
 	/// Constructs a new URL object from its components.
@@ -66,45 +68,40 @@
 			str = str[idx+1 .. $];
 			bool requires_host = false;
 
-			switch(m_schema){
-				case "http":
-				case "https":
-				case "ftp":
-				case "spdy":
-				case "sftp":
-				case "file":
-					// proto://server/path style
-					enforce(str.startsWith("//"), "URL must start with proto://...");
-					requires_host = true;
-					str = str[2 .. $];
-					goto default;
-				default:
-					auto si = str.countUntil('/');
-					if( si < 0 ) si = str.length;
-					auto ai = str[0 .. si].countUntil('@');
-					sizediff_t hs = 0;
-					if( ai >= 0 ){
-						hs = ai+1;
-						auto ci = str[0 .. ai].countUntil(':');
-						if( ci >= 0 ){
-							m_username = str[0 .. ci];
-							m_password = str[ci+1 .. ai];
-						} else m_username = str[0 .. ai];
-						enforce(m_username.length > 0, "Empty user name in URL.");
-					}
-
-					m_host = str[hs .. si];
-					auto pi = m_host.countUntil(':');
-					if(pi > 0) {
-						enforce(pi < m_host.length-1, "Empty port in URL.");
-						m_port = to!ushort(m_host[pi+1..$]);
-						m_host = m_host[0 .. pi];
-					}
-
-					enforce(!requires_host || m_schema == "file" || m_host.length > 0,
-							"Empty server name in URL.");
-					str = str[si .. $];
+			auto schema_parts = m_schema.split("+");
+			if (!schema_parts.empty && schema_parts.back.canFind(m_schemes))
+			{
+				// proto://server/path style
+				enforce(str.startsWith("//"), "URL must start with proto://...");
+				requires_host = true;
+				str = str[2 .. $];
 			}
+
+			auto si = str.countUntil('/');
+			if( si < 0 ) si = str.length;
+			auto ai = str[0 .. si].countUntil('@');
+			sizediff_t hs = 0;
+			if( ai >= 0 ){
+				hs = ai+1;
+				auto ci = str[0 .. ai].countUntil(':');
+				if( ci >= 0 ){
+					m_username = str[0 .. ci];
+					m_password = str[ci+1 .. ai];
+				} else m_username = str[0 .. ai];
+				enforce(m_username.length > 0, "Empty user name in URL.");
+			}
+
+			m_host = str[hs .. si];
+			auto pi = m_host.countUntil(':');
+			if(pi > 0) {
+				enforce(pi < m_host.length-1, "Empty port in URL.");
+				m_port = to!ushort(m_host[pi+1..$]);
+				m_host = m_host[0 .. pi];
+			}
+
+			enforce(!requires_host || m_schema == "file" || m_host.length > 0,
+				"Empty server name in URL.");
+			str = str[si .. $];
 		}
 
 		this.localURI = (str == "") ? "/" : str;
@@ -215,16 +212,10 @@
 		auto dst = appender!string();
 		dst.put(schema);
 		dst.put(":");
-		switch(schema){
-			default: break;
-			case "file":
-			case "http":
-			case "https":
-			case "ftp":
-			case "spdy":
-			case "sftp":
-				dst.put("//");
-				break;
+		auto schema_parts = schema.split("+");
+		if (!schema_parts.empty && schema_parts.back.canFind(m_schemes))
+		{
+			dst.put("//");
 		}
 		dst.put(host);
 		if( m_port > 0 ) formattedWrite(dst, ":%d", m_port);
@@ -283,4 +274,9 @@
 
 	url = URL("http://localhost/")~NativePath("packages");
 	assert(url.toString() == "http://localhost/packages", url.toString());
+
+	url = URL.parse("dub+https://code.dlang.org/");
+	assert(url.host == "code.dlang.org");
+	assert(url.toString() == "dub+https://code.dlang.org/");
+	assert(url.schema == "dub+https");
 }
diff --git a/source/dub/package_.d b/source/dub/package_.d
index 8a2e6f6..bac7020 100644
--- a/source/dub/package_.d
+++ b/source/dub/package_.d
@@ -409,6 +409,7 @@
 				case "profile-gc": settings.addOptions(profileGC, debugInfo); break;
 				case "cov": settings.addOptions(coverage, debugInfo); break;
 				case "unittest-cov": settings.addOptions(unittests, coverage, debugMode, debugInfo); break;
+				case "syntax": settings.addOptions(syntaxOnly); break;
 			}
 		}
 	}
diff --git a/source/dub/project.d b/source/dub/project.d
index 277b92b..d01fe41 100644
--- a/source/dub/project.d
+++ b/source/dub/project.d
@@ -614,16 +614,16 @@
 	 *
 	 * Params:
 	 *   dst = The BuildSettings struct to fill with data.
-	 *   platform = The platform to retrieve the values for.
+	 *   gsettings = The generator settings to retrieve the values for.
 	 *   config = Values of the given configuration will be retrieved.
 	 *   root_package = If non null, use it instead of the project's real root package.
 	 *   shallow = If true, collects only build settings for the main package (including inherited settings) and doesn't stop on target type none and sourceLibrary.
 	 */
-	void addBuildSettings(ref BuildSettings dst, in BuildPlatform platform, string config, in Package root_package = null, bool shallow = false)
+	void addBuildSettings(ref BuildSettings dst, in GeneratorSettings gsettings, string config, in Package root_package = null, bool shallow = false)
 	const {
 		import dub.internal.utils : stripDlangSpecialChars;
 
-		auto configs = getPackageConfigs(platform, config);
+		auto configs = getPackageConfigs(gsettings.platform, config);
 
 		foreach (pkg; this.getTopologicalPackageList(false, root_package, configs)) {
 			auto pkg_path = pkg.path.toNativeString();
@@ -632,11 +632,11 @@
 			assert(pkg.name in configs, "Missing configuration for "~pkg.name);
 			logDebug("Gathering build settings for %s (%s)", pkg.name, configs[pkg.name]);
 
-			auto psettings = pkg.getBuildSettings(platform, configs[pkg.name]);
+			auto psettings = pkg.getBuildSettings(gsettings.platform, configs[pkg.name]);
 			if (psettings.targetType != TargetType.none) {
 				if (shallow && pkg !is m_rootPackage)
 					psettings.sourceFiles = null;
-				processVars(dst, this, pkg, psettings);
+				processVars(dst, this, pkg, psettings, gsettings);
 				if (psettings.importPaths.empty)
 					logWarn(`Package %s (configuration "%s") defines no import paths, use {"importPaths": [...]} or the default package directory structure to fix this.`, pkg.name, configs[pkg.name]);
 				if (psettings.mainSourceFile.empty && pkg is m_rootPackage && psettings.targetType == TargetType.executable)
@@ -651,15 +651,15 @@
 				dst.targetPath = psettings.targetPath;
 				dst.targetName = psettings.targetName;
 				if (!psettings.workingDirectory.empty)
-					dst.workingDirectory = processVars(psettings.workingDirectory, this, pkg, true);
+					dst.workingDirectory = processVars(psettings.workingDirectory, this, pkg, gsettings, true);
 				if (psettings.mainSourceFile.length)
-					dst.mainSourceFile = processVars(psettings.mainSourceFile, this, pkg, true);
+					dst.mainSourceFile = processVars(psettings.mainSourceFile, this, pkg, gsettings, true);
 			}
 		}
 
 		// always add all version identifiers of all packages
 		foreach (pkg; this.getTopologicalPackageList(false, null, configs)) {
-			auto psettings = pkg.getBuildSettings(platform, configs[pkg.name]);
+			auto psettings = pkg.getBuildSettings(gsettings.platform, configs[pkg.name]);
 			dst.addVersions(psettings.versions);
 		}
 	}
@@ -668,18 +668,18 @@
 
 		Params:
 			dst = The `BuildSettings` instance to add the build settings to
-			platform = Target build platform
+			gsettings = Target generator settings
 			build_type = Name of the build type
 			for_root_package = Selects if the build settings are for the root
 				package or for one of the dependencies. Unittest flags will
 				only be added to the root package.
 	*/
-	void addBuildTypeSettings(ref BuildSettings dst, in BuildPlatform platform, string build_type, bool for_root_package = true)
+	void addBuildTypeSettings(ref BuildSettings dst, in GeneratorSettings gsettings, bool for_root_package = true)
 	{
 		bool usedefflags = !(dst.requirements & BuildRequirement.noDefaultFlags);
 		if (usedefflags) {
 			BuildSettings btsettings;
-			m_rootPackage.addBuildTypeSettings(btsettings, platform, build_type);
+			m_rootPackage.addBuildTypeSettings(btsettings, gsettings.platform, gsettings.buildType);
 
 			if (!for_root_package) {
 				// don't propagate unittest switch to dependencies, as dependent
@@ -688,7 +688,7 @@
 				btsettings.removeOptions(BuildOption.unittests);
 			}
 
-			processVars(dst, this, m_rootPackage, btsettings);
+			processVars(dst, this, m_rootPackage, btsettings, gsettings);
 		}
 	}
 
@@ -1067,41 +1067,14 @@
 			m_selections.save(path);
 	}
 
-	/** Checks if the cached upgrade information is still considered up to date.
-
-		The cache will be considered out of date after 24 hours after the last
-		online check.
-	*/
-	bool isUpgradeCacheUpToDate()
+	deprecated bool isUpgradeCacheUpToDate()
 	{
-		try {
-			auto datestr = m_packageSettings["dub"].opt!(Json[string]).get("lastUpgrade", Json("")).get!string;
-			if (!datestr.length) return false;
-			auto date = SysTime.fromISOExtString(datestr);
-			if ((Clock.currTime() - date) > 1.days) return false;
-			return true;
-		} catch (Exception t) {
-			logDebug("Failed to get the last upgrade time: %s", t.msg);
-			return false;
-		}
+		return false;
 	}
 
-	/** Returns the currently cached upgrade information.
-
-		The returned dictionary maps from dependency package name to the latest
-		available version that matches the dependency specifications.
-	*/
-	Dependency[string] getUpgradeCache()
+	deprecated Dependency[string] getUpgradeCache()
 	{
-		try {
-			Dependency[string] ret;
-			foreach (string p, d; m_packageSettings["dub"].opt!(Json[string]).get("cachedUpgrades", Json.emptyObject))
-				ret[p] = SelectedVersions.dependencyFromJson(d);
-			return ret;
-		} catch (Exception t) {
-			logDebug("Failed to get cached upgrades: %s", t.msg);
-			return null;
-		}
+		return null;
 	}
 
 	/** Sets a new set of versions for the upgrade cache.
@@ -1165,75 +1138,55 @@
 }
 
 void processVars(ref BuildSettings dst, in Project project, in Package pack,
-	BuildSettings settings, bool include_target_settings = false)
+	BuildSettings settings, in GeneratorSettings gsettings, bool include_target_settings = false)
 {
-	dst.addDFlags(processVars(project, pack, settings.dflags));
-	dst.addLFlags(processVars(project, pack, settings.lflags));
-	dst.addLibs(processVars(project, pack, settings.libs));
-	dst.addSourceFiles(processVars(project, pack, settings.sourceFiles, true));
-	dst.addImportFiles(processVars(project, pack, settings.importFiles, true));
-	dst.addStringImportFiles(processVars(project, pack, settings.stringImportFiles, true));
-	dst.addCopyFiles(processVars(project, pack, settings.copyFiles, true));
-	dst.addVersions(processVars(project, pack, settings.versions));
-	dst.addDebugVersions(processVars(project, pack, settings.debugVersions));
-	dst.addImportPaths(processVars(project, pack, settings.importPaths, true));
-	dst.addStringImportPaths(processVars(project, pack, settings.stringImportPaths, true));
-	dst.addPreGenerateCommands(processVars(project, pack, settings.preGenerateCommands));
-	dst.addPostGenerateCommands(processVars(project, pack, settings.postGenerateCommands));
-	dst.addPreBuildCommands(processVars(project, pack, settings.preBuildCommands));
-	dst.addPostBuildCommands(processVars(project, pack, settings.postBuildCommands));
+	dst.addDFlags(processVars(project, pack, gsettings, settings.dflags));
+	dst.addLFlags(processVars(project, pack, gsettings, settings.lflags));
+	dst.addLibs(processVars(project, pack, gsettings, settings.libs));
+	dst.addSourceFiles(processVars(project, pack, gsettings, settings.sourceFiles, true));
+	dst.addImportFiles(processVars(project, pack, gsettings, settings.importFiles, true));
+	dst.addStringImportFiles(processVars(project, pack, gsettings, settings.stringImportFiles, true));
+	dst.addCopyFiles(processVars(project, pack, gsettings, settings.copyFiles, true));
+	dst.addVersions(processVars(project, pack, gsettings, settings.versions));
+	dst.addDebugVersions(processVars(project, pack, gsettings, settings.debugVersions));
+	dst.addImportPaths(processVars(project, pack, gsettings, settings.importPaths, true));
+	dst.addStringImportPaths(processVars(project, pack, gsettings, settings.stringImportPaths, true));
+	dst.addPreGenerateCommands(processVars(project, pack, gsettings, settings.preGenerateCommands));
+	dst.addPostGenerateCommands(processVars(project, pack, gsettings, settings.postGenerateCommands));
+	dst.addPreBuildCommands(processVars(project, pack, gsettings, settings.preBuildCommands));
+	dst.addPostBuildCommands(processVars(project, pack, gsettings, settings.postBuildCommands));
 	dst.addRequirements(settings.requirements);
 	dst.addOptions(settings.options);
 
 	if (include_target_settings) {
 		dst.targetType = settings.targetType;
-		dst.targetPath = processVars(settings.targetPath, project, pack, true);
+		dst.targetPath = processVars(settings.targetPath, project, pack, gsettings, true);
 		dst.targetName = settings.targetName;
 		if (!settings.workingDirectory.empty)
-			dst.workingDirectory = processVars(settings.workingDirectory, project, pack, true);
+			dst.workingDirectory = processVars(settings.workingDirectory, project, pack, gsettings, true);
 		if (settings.mainSourceFile.length)
-			dst.mainSourceFile = processVars(settings.mainSourceFile, project, pack, true);
+			dst.mainSourceFile = processVars(settings.mainSourceFile, project, pack, gsettings, true);
 	}
 }
 
-private string[] processVars(in Project project, in Package pack, string[] vars, bool are_paths = false)
+private string[] processVars(in Project project, in Package pack, in GeneratorSettings gsettings, string[] vars, bool are_paths = false)
 {
 	auto ret = appender!(string[])();
-	processVars(ret, project, pack, vars, are_paths);
+	processVars(ret, project, pack, gsettings, vars, are_paths);
 	return ret.data;
 
 }
-private void processVars(ref Appender!(string[]) dst, in Project project, in Package pack, string[] vars, bool are_paths = false)
+private void processVars(ref Appender!(string[]) dst, in Project project, in Package pack, in GeneratorSettings gsettings, string[] vars, bool are_paths = false)
 {
-	foreach (var; vars) dst.put(processVars(var, project, pack, are_paths));
+	foreach (var; vars) dst.put(processVars(var, project, pack, gsettings, are_paths));
 }
 
-private string processVars(string var, in Project project, in Package pack, bool is_path)
+private string processVars(Project, Package)(string var, in Project project, in Package pack,in GeneratorSettings gsettings, bool is_path)
 {
-	auto idx = std.string.indexOf(var, '$');
-	if (idx >= 0) {
-		auto vres = appender!string();
-		while (idx >= 0) {
-			if (idx+1 >= var.length) break;
-			if (var[idx+1] == '$') {
-				vres.put(var[0 .. idx+1]);
-				var = var[idx+2 .. $];
-			} else {
-				vres.put(var[0 .. idx]);
-				var = var[idx+1 .. $];
+	import std.regex : regex, replaceAll;
 
-				size_t idx2 = 0;
-				while( idx2 < var.length && isIdentChar(var[idx2]) ) idx2++;
-				auto varname = var[0 .. idx2];
-				var = var[idx2 .. $];
-
-				vres.put(getVariable(varname, project, pack));
-			}
-			idx = std.string.indexOf(var, '$');
-		}
-		vres.put(var);
-		var = vres.data;
-	}
+	auto varRE = regex(`\$([\w_]+)|\$\{([\w_]+)\}`);
+	var = var.replaceAll!(m => getVariable(m[1].length ? m[1] : m[2], project, pack, gsettings))(varRE);
 	if (is_path) {
 		auto p = NativePath(var);
 		if (!p.absolute) {
@@ -1242,19 +1195,65 @@
 	} else return var;
 }
 
-private string getVariable(string name, in Project project, in Package pack)
+// Keep the following list up-to-date if adding more build settings variables.
+/// List of variables that can be used in build settings
+package(dub) immutable buildSettingsVars = [
+	"ARCH", "PLATFORM", "PLATFORM_POSIX", "BUILD_TYPE"
+];
+
+private string getVariable(Project, Package)(string name, in Project project, in Package pack, in GeneratorSettings gsettings)
 {
 	import std.process : environment;
-	if (name == "PACKAGE_DIR") return pack.path.toNativeString();
-	if (name == "ROOT_PACKAGE_DIR") return project.rootPackage.path.toNativeString();
+	import std.uni : asUpperCase;
+	NativePath path;
+	if (name == "PACKAGE_DIR")
+		path = pack.path;
+	else if (name == "ROOT_PACKAGE_DIR")
+		path = project.rootPackage.path;
 
 	if (name.endsWith("_PACKAGE_DIR")) {
 		auto pname = name[0 .. $-12];
 		foreach (prj; project.getTopologicalPackageList())
-			if (prj.name.toUpper().replace("-", "_") == pname)
-				return prj.path.toNativeString();
+			if (prj.name.asUpperCase.map!(a => a == '-' ? '_' : a).equal(pname))
+			{
+				path = prj.path;
+				break;
+			}
 	}
 
+	if (!path.empty)
+	{
+		// no trailing slash for clean path concatenation (see #1392)
+		path.endsWithSlash = false;
+		return path.toNativeString();
+	}
+
+	if (name == "ARCH") {
+		foreach (a; gsettings.platform.architecture)
+			return a;
+		return "";
+	}
+
+	if (name == "PLATFORM") {
+		import std.algorithm : filter;
+		foreach (p; gsettings.platform.platform.filter!(p => p != "posix"))
+			return p;
+		foreach (p; gsettings.platform.platform)
+			return p;
+		return "";
+	}
+
+	if (name == "PLATFORM_POSIX") {
+		import std.algorithm : canFind;
+		if (gsettings.platform.platform.canFind("posix"))
+			return "posix";
+		foreach (p; gsettings.platform.platform)
+			return p;
+		return "";
+	}
+
+	if (name == "BUILD_TYPE") return gsettings.buildType;
+
 	auto envvar = environment.get(name);
 	if (envvar !is null) return envvar;
 
@@ -1262,6 +1261,65 @@
 }
 
 
+unittest
+{
+	static struct MockPackage
+	{
+		this(string name)
+		{
+			this.name = name;
+			version (Posix)
+				path = NativePath("/pkgs/"~name);
+			else version (Windows)
+				path = NativePath(`C:\pkgs\`~name);
+			// see 4d4017c14c, #268, and #1392 for why this all package paths end on slash internally
+			path.endsWithSlash = true;
+		}
+		string name;
+		NativePath path;
+	}
+
+	static struct MockProject
+	{
+		MockPackage rootPackage;
+		inout(MockPackage)[] getTopologicalPackageList() inout
+		{
+			return _dependencies;
+		}
+	private:
+		MockPackage[] _dependencies;
+	}
+
+	MockProject proj = {
+		rootPackage: MockPackage("root"),
+		_dependencies: [MockPackage("dep1"), MockPackage("dep2")]
+	};
+	auto pack = MockPackage("test");
+	GeneratorSettings gsettings;
+	enum isPath = true;
+
+	import std.path : dirSeparator;
+
+	static Path woSlash(Path p) { p.endsWithSlash = false; return p; }
+	// basic vars
+	assert(processVars("Hello $PACKAGE_DIR", proj, pack, gsettings, !isPath) == "Hello "~woSlash(pack.path).toNativeString);
+	assert(processVars("Hello $ROOT_PACKAGE_DIR", proj, pack, gsettings, !isPath) == "Hello "~woSlash(proj.rootPackage.path).toNativeString.chomp(dirSeparator));
+	assert(processVars("Hello $DEP1_PACKAGE_DIR", proj, pack, gsettings, !isPath) == "Hello "~woSlash(proj._dependencies[0].path).toNativeString);
+	// ${VAR} replacements
+	assert(processVars("Hello ${PACKAGE_DIR}"~dirSeparator~"foobar", proj, pack, gsettings, !isPath) == "Hello "~(pack.path ~ "foobar").toNativeString);
+	assert(processVars("Hello $PACKAGE_DIR"~dirSeparator~"foobar", proj, pack, gsettings, !isPath) == "Hello "~(pack.path ~ "foobar").toNativeString);
+	// test with isPath
+	assert(processVars("local", proj, pack, gsettings, isPath) == (pack.path ~ "local").toNativeString);
+	// test other env variables
+	import std.process : environment;
+	environment["MY_ENV_VAR"] = "blablabla";
+	assert(processVars("$MY_ENV_VAR", proj, pack, gsettings, !isPath) == "blablabla");
+	assert(processVars("${MY_ENV_VAR}suffix", proj, pack, gsettings, !isPath) == "blablablasuffix");
+	assert(processVars("$MY_ENV_VAR-suffix", proj, pack, gsettings, !isPath) == "blablabla-suffix");
+	assert(processVars("$MY_ENV_VAR:suffix", proj, pack, gsettings, !isPath) == "blablabla:suffix");
+	environment.remove("MY_ENV_VAR");
+}
+
 /** Holds and stores a set of version selections for package dependencies.
 
 	This is the runtime representation of the information contained in
@@ -1446,4 +1504,3 @@
 			m_selections[p] = Selected(dependencyFromJson(v));
 	}
 }
-
diff --git a/source/dub/recipe/packagerecipe.d b/source/dub/recipe/packagerecipe.d
index 30873b5..7775bdb 100644
--- a/source/dub/recipe/packagerecipe.d
+++ b/source/dub/recipe/packagerecipe.d
@@ -188,7 +188,13 @@
 					auto path = NativePath(spath);
 					if (!path.absolute) path = base_path ~ path;
 					if (!existsFile(path) || !isDir(path.toNativeString())) {
-						logWarn("Invalid source/import path: %s", path.toNativeString());
+						import dub.project : buildSettingsVars;
+						import std.algorithm : any, find;
+						const hasVar = buildSettingsVars.any!((string var) {
+							return spath.find("$"~var).length > 0 || spath.find("${"~var~"}").length > 0;
+						});
+						if (!hasVar)
+							logWarn("Invalid source/import path: %s", path.toNativeString());
 						continue;
 					}
 
diff --git a/test/expected-issue1037-output b/test/expected-issue1037-output
index a5d7c55..e03b110 100644
--- a/test/expected-issue1037-output
+++ b/test/expected-issue1037-output
@@ -1,4 +1,3 @@
-Root package issue1037-better-dependency-messages reference gitcompatibledubpackage 1.0.1 cannot be satisfied.
-Packages causing the conflict:
-	issue1037-better-dependency-messages depends on 1.0.1
-	b depends on ~>1.0.2
+Unresolvable dependencies to package gitcompatibledubpackage:
+  b >=0.0.0 @DIR/b depends on gitcompatibledubpackage ~>1.0.2
+  issue1037-better-dependency-messages ~master depends on gitcompatibledubpackage 1.0.1
diff --git a/test/issue1037-better-dependency-messages.sh b/test/issue1037-better-dependency-messages.sh
index 2fe3b9f..c06bdc4 100755
--- a/test/issue1037-better-dependency-messages.sh
+++ b/test/issue1037-better-dependency-messages.sh
@@ -4,17 +4,21 @@
 cd ${CURR_DIR}/issue1037-better-dependency-messages
 
 temp_file=$(mktemp $(basename $0).XXXXXX)
+temp_file2=$(mktemp $(basename $0).XXXXXX)
 expected_file="$CURR_DIR/expected-issue1037-output"
 
 function cleanup {
-    rm $temp_file
+    rm -f $temp_file
+    rm -f $temp_file
 }
 
 trap cleanup EXIT
 
+sed "s#DIR#$CURR_DIR/issue1037-better-dependency-messages#" "$expected_file" > "$temp_file2"
+
 $DUB upgrade 2>$temp_file && exit 1 # dub upgrade should fail
 
-if ! diff "$expected_file" "$temp_file"; then
+if ! diff "$temp_file2" "$temp_file"; then
     die 'output not containing conflict information'
 fi
 
diff --git a/test/issue1158-stdin-for-single-files.sh b/test/issue1158-stdin-for-single-files.sh
new file mode 100755
index 0000000..1d2baea
--- /dev/null
+++ b/test/issue1158-stdin-for-single-files.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+. $(dirname "${BASH_SOURCE[0]}")/common.sh
+
+cd ${CURR_DIR}/issue1158-stdin-for-single-files
+
+if ! { cat stdin.d | ${DUB} - --value=v 2>&1 || true; } | grep -cF '["--value=v"]'; then
+	die $LINENO 'Stdin for single files failed.'
+fi
\ No newline at end of file
diff --git a/test/issue1158-stdin-for-single-files/.no_build b/test/issue1158-stdin-for-single-files/.no_build
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/issue1158-stdin-for-single-files/.no_build
diff --git a/test/issue1158-stdin-for-single-files/stdin.d b/test/issue1158-stdin-for-single-files/stdin.d
new file mode 100644
index 0000000..120a14a
--- /dev/null
+++ b/test/issue1158-stdin-for-single-files/stdin.d
@@ -0,0 +1,7 @@
+/+ dub.sdl:
+	name "hello"
++/
+void main(string[] args) {
+	import std.stdio : writeln;
+	writeln(args[1..$]);
+}
\ No newline at end of file
diff --git a/test/issue1447-build-settings-vars.sh b/test/issue1447-build-settings-vars.sh
new file mode 100755
index 0000000..5f60e06
--- /dev/null
+++ b/test/issue1447-build-settings-vars.sh
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -e
+
+. $(dirname "${BASH_SOURCE[0]}")/common.sh
+
+if [[ `uname -m` == "x86_64" ]]; then
+    ARCH=x86_64
+else
+    ARCH=x86
+fi
+
+rm -rf ${CURR_DIR}/issue1447-build-settings-vars/.dub
+rm -rf ${CURR_DIR}/issue1447-build-settings-vars/test
+
+${DUB} build --root ${CURR_DIR}/issue1447-build-settings-vars --arch=$ARCH
+OUTPUT=`${CURR_DIR}/issue1447-build-settings-vars/test`
+
+rm -rf ${CURR_DIR}/issue1447-build-settings-vars/.dub
+rm -rf ${CURR_DIR}/issue1447-build-settings-vars/test
+
+if [[ "$OUTPUT" != "$ARCH" ]]; then die "Build settings ARCH var incorrect"; fi
diff --git a/test/issue1447-build-settings-vars/.no_run b/test/issue1447-build-settings-vars/.no_run
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/issue1447-build-settings-vars/.no_run
diff --git a/test/issue1447-build-settings-vars/.no_test b/test/issue1447-build-settings-vars/.no_test
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/issue1447-build-settings-vars/.no_test
diff --git a/test/issue1447-build-settings-vars/dub.json b/test/issue1447-build-settings-vars/dub.json
new file mode 100644
index 0000000..9f5d345
--- /dev/null
+++ b/test/issue1447-build-settings-vars/dub.json
@@ -0,0 +1,4 @@
+{
+	"name": "test",
+	"stringImportPaths": ["view-$ARCH"]
+}
\ No newline at end of file
diff --git a/test/issue1447-build-settings-vars/source/app.d b/test/issue1447-build-settings-vars/source/app.d
new file mode 100644
index 0000000..3e94dfc
--- /dev/null
+++ b/test/issue1447-build-settings-vars/source/app.d
@@ -0,0 +1,6 @@
+import std.stdio;
+
+void main()
+{
+	writeln(import("arch"));
+}
diff --git a/test/issue1447-build-settings-vars/view-x86/arch b/test/issue1447-build-settings-vars/view-x86/arch
new file mode 100644
index 0000000..f4bad79
--- /dev/null
+++ b/test/issue1447-build-settings-vars/view-x86/arch
@@ -0,0 +1 @@
+x86
\ No newline at end of file
diff --git a/test/issue1447-build-settings-vars/view-x86_64/arch b/test/issue1447-build-settings-vars/view-x86_64/arch
new file mode 100644
index 0000000..8790996
--- /dev/null
+++ b/test/issue1447-build-settings-vars/view-x86_64/arch
@@ -0,0 +1 @@
+x86_64
\ No newline at end of file