diff --git a/source/app.d b/source/app.d
index 2256407..660cca1 100644
--- a/source/app.d
+++ b/source/app.d
@@ -144,11 +144,25 @@
 				if( install_version.length ) dub.install(name, new Dependency(install_version), location);
 				else {
 					try dub.install(name, new Dependency(">=0.0.0"), location);
-					catch(Exception) dub.install(name, new Dependency("~master"), location);
+					catch(Exception e){
+						logInfo("Installing a release version failed: %s", e.msg);
+						logInfo("Retry with ~master...");
+						dub.install(name, new Dependency("~master"), location);
+					}
 				}
 				break;
 			case "uninstall":
-				enforce("Not implemented.");
+				enforce(args.length >= 2, "Missing package name.");
+				/*auto location = InstallLocation.UserWide;
+				auto name = args[1];
+				enforce(!install_local || !install_system, "Cannot install locally and system wide at the same time.");
+				if( install_local ) location = InstallLocation.Local;
+				else if( install_system ) location = InstallLocation.SystemWide;
+				if( install_version.length ) dub.uninstall(name, new Dependency(install_version), location);
+				else {
+					assert(false);
+				}*/
+				enforce(false, "Not implemented.");
 				break;
 			case "add-local":
 				enforce(args.length >= 3, "Missing arguments.");
diff --git a/source/dub/dub.d b/source/dub/dub.d
index d92963f..ada3624 100644
--- a/source/dub/dub.d
+++ b/source/dub/dub.d
@@ -191,16 +191,17 @@
 		auto pinfo = m_packageSupplier.packageJson(packageId, dep);
 		string ver = pinfo["version"].get!string;
 
-		logInfo("Installing %s %s...", packageId, ver);
+		logInfo("Downloading %s %s...", packageId, ver);
 
-		logDebug("Aquiring package zip file");
+		logDebug("Acquiring package zip file");
 		auto dload = m_root ~ ".dub/temp/downloads";
-		auto tempFile = m_tempPath ~ ("dub-download-"~packageId~"-"~ver~".zip");
-		string sTempFile = to!string(tempFile);
-		if(exists(sTempFile)) remove(sTempFile);
+		auto tempfname = packageId ~ "-" ~ (ver.startsWith('~') ? ver[1 .. $] : ver) ~ ".zip";
+		auto tempFile = m_tempPath ~ tempfname;
+		if( existsFile(tempFile) ) removeFile(tempFile);
 		m_packageSupplier.storePackage(tempFile, packageId, dep); // Q: continue on fail?
-		scope(exit) remove(sTempFile);
+		scope(exit) removeFile(tempFile);
 
+		logInfo("Installing %s %s...", packageId, ver);
 		m_packageManager.install(tempFile, pinfo, location);
 	}
 
diff --git a/source/dub/installation.d b/source/dub/installation.d
index 524c40f..af92ca9 100644
--- a/source/dub/installation.d
+++ b/source/dub/installation.d
Binary files differ
diff --git a/source/dub/package_.d b/source/dub/package_.d
index b949b39..8fceb36 100644
--- a/source/dub/package_.d
+++ b/source/dub/package_.d
@@ -187,8 +187,6 @@
 	void writeJson(Path path) {
 		auto dstFile = openFile((path~PackageJsonFilename).toString(), FileMode.CreateTrunc);
 		scope(exit) dstFile.close();
-		Appender!string js;
-		toPrettyJson(js, m_meta);
-		dstFile.write( js.data );
+		dstFile.writePrettyJsonString(m_meta);
 	}
 }
\ No newline at end of file
diff --git a/source/dub/packagemanager.d b/source/dub/packagemanager.d
index 61dcdd4..5e5362e 100644
--- a/source/dub/packagemanager.d
+++ b/source/dub/packagemanager.d
@@ -16,6 +16,7 @@
 import std.conv;
 import std.exception;
 import std.file;
+import std.string;
 import std.zip;
 import vibe.core.file;
 import vibe.core.log;
@@ -169,7 +170,7 @@
 		}
 
 		if( existsFile(destination) )
-			throw new Exception(package_name~" needs to be uninstalled prior installation.");
+			throw new Exception(format("%s %s needs to be uninstalled prior installation.", package_name, package_version));
 
 		// open zip file
 		ZipArchive archive;
diff --git a/source/dub/packagesupplier.d b/source/dub/packagesupplier.d
index b3f6edf..f72ada5 100644
--- a/source/dub/packagesupplier.d
+++ b/source/dub/packagesupplier.d
@@ -39,13 +39,13 @@
 		enforce(path.absolute);
 		logInfo("Storing package '"~packageId~"', version requirements: %s", dep);
 		auto filename = bestPackageFile(packageId, dep);
-		enforce( exists(to!string(filename)) );
-		copy(to!string(filename), to!string(path));
+		enforce(existsFile(filename));
+		copyFile(filename, path);
 	}
 	
 	Json packageJson(const string packageId, const Dependency dep) {
 		auto filename = bestPackageFile(packageId, dep);
-		return jsonFromZip(to!string(filename), "package.json");
+		return jsonFromZip(filename, "package.json");
 	}
 	
 	private Path bestPackageFile( const string packageId, const Dependency dep) const {
@@ -64,7 +64,7 @@
 		
 		auto fileName = m_path ~ (packageId ~ "_" ~ to!string(bestVersion) ~ ".zip");
 		
-		if(bestVersion == Version.RELEASE || !exists(to!string(fileName)))
+		if(bestVersion == Version.RELEASE || !existsFile(fileName))
 			throw new Exception("No matching package found");
 		
 		logDebug("Found best matching package: '%s'", fileName);
diff --git a/source/dub/project.d b/source/dub/project.d
index aae2f8e..8a5f0d7 100644
--- a/source/dub/project.d
+++ b/source/dub/project.d
@@ -416,9 +416,7 @@
 			if( !exists(dubpath.toNativeString()) ) mkdir(dubpath.toNativeString());
 			auto dstFile = openFile((dubpath~"dub.json").toString(), FileMode.CreateTrunc);
 			scope(exit) dstFile.close();
-			Appender!string js;
-			toPrettyJson(js, m_json);
-			dstFile.write( js.data );
+			dstFile.writePrettyJsonString(m_json);
 		} catch( Exception e ){
 			logWarn("Could not write .dub/dub.json.");
 		}
diff --git a/source/dub/utils.d b/source/dub/utils.d
index d890bf4..f6f4fd7 100644
--- a/source/dub/utils.d
+++ b/source/dub/utils.d
@@ -38,7 +38,7 @@
 	return parseJson(text);
 }
 
-package Json jsonFromZip(string zip, string filename) {
+package Json jsonFromZip(Path zip, string filename) {
 	auto f = openFile(zip, FileMode.Read);
 	ubyte[] b = new ubyte[cast(uint)f.leastSize];
 	f.read(b);
@@ -52,7 +52,7 @@
 {
 	auto f = openFile(path, FileMode.CreateTrunc);
 	scope(exit) f.close();
-	toPrettyJson(f, json);
+	f.writePrettyJsonString(json);
 }
 
 package bool isPathFromZip(string p) {