Linking error with LDC on Win64 due to strange subpackage libs-ldc

[kinke]

Testing dub (v1.1) and vibe.d (v0.7.30) with an early LDC 1.1 (ldc-developers/ldc#1891), a project template cannot be linked on Win64 due to missing z.lib. This seems to come in via vibe.d's subpackages in %AppData%\dub\packages\vibe-d-0.7.30\vibe-d\dub.json, where there's a "libs-ldc": [ "z" ] item. Removing it gets the project to compile, link and run successfully, with both LDC2 and LDMD2.

I did a quick test on Ubuntu 16.04 (x86_64), removed the subpackage as well (and worked around #1611 with a manually added OpenSSL dependency), and it's also working. So this LDC-specific dependency (on zlib apparently) may not be required after all (isn't it part of druntime Phobos?) and only causes trouble on Windows.

[s-ludwig]

I had to add the explicit dependency a while ago (9df23d4, same was done for GDC: #1607). Did the build succeed on Linux without removing it? If that's the case, I would suggest to change this to "libs-ldc-posix": ["z"], so that older versions of LDC also still work, at least on Linux/macOS.

[kinke]

Did the build succeed on Linux without removing it?

It did. So your suggested fix makes sense, although zlib should be part of libphobos2-ldc for quite a while now.

[s-ludwig]

Okay, I'll change it like that then. Based on the context of my commit, I guess that LDC 1.0.0 was still affected by this, which is still the latest stable release, so I'd like to keep the workaround for a while still.