We see this assert triggered frequently, even sometimes in production,
so at least make it easier to track down the data involved.

mkdirRecurse will not do anything if the directory already exists,
so there is no need to call existsDirectory.

As it is not available on all platforms, we can't really rely
on it for code, and it is indeed not used anywhere.

This was triggering an assert error with vibe-d path.
The recursion logic was a bit murky, so the function
is now split in 3 different part and better documented.

This gets the unittest framework closer to the actual behavior,
and allows us to mock basic FS operations such as mkdir and writeFile.
Further improvements can be made to support more operations,
and to have package setup done before `TestDub` instantiation.

This reduces the number of deprecations issued in dub.

In practice we only every iterate directories in a foreach,
which means iterateDirectory is the only function ever used.

It was actually unused, because al the call sites were doing a useless
round-trip from NativePath to string to NativePath.
There is no need for it anymore so we can just remove it to avoid
this kind of mistakes in the future.

All usages actually want to ensure the directory is present,
and don't care about having a separation between existence check
and creation.

It doesn't make sense to have those in two separate modules.

This removes the range API and instead uses Appender,
while using a limited and centralized set of functions
to read/write from files.
The end goal is to permit dependency injection,
which is a pre-requisite to extending the test-suite.

We don't actually use URL here, nor should we,
we use path, so correct the import.

This was wrong on many level:
- The missing `else` clause meant that the `enforce` clause was always there on Windows;
- The `enforce("Reason")` should have been `enforce(false, "Reason")`,
  as in its current form it would never fail and not serve its intended purpose;
- It was pushing at runtime something that was easily detected at CT;

I simply aliases the new dub.logging module, printing a deprecation
message while compiling

The new module replaces dub.internal.vibecompat.core.log by using the
same function names, but implementing colored output and the left
fixed-width tag. Overloaded functions are provided to output colored
text.

Still missing initLogging() and non-TTY stdout/stderr detection

* Add missing attributes to NativePath.empty

* Dependency: Change format for path-based dependencies

So SumType infers its opEquals and co as safe.

Fixes dip1000 error.

Make sure a recent enough Vibe.d is used so we can update the vibecompat code.
Additionally, since the split of Vibe.d into package, and the splitting of
vibe-core into its own project, the version specification was never triggered,
so it was corrected in this commit (the version spec was correct for older Vibe.d).

There are plenty left, but those ones didn't seem to have any side effect.