Also emit DEP_Z_INCLUDE when using pkg-config

[sfackler]

Downstream build scripts use DEP_Z_INCLUDE to configure the builds of other native libraries (for example in libgit2-sys). Previously, if libz was found via pkg-config and didn't have a system-default include directory those builds would fail.

[Byron]

Thanks a lot for the fix!

It looks good to me, but I wouldn't know how to test it, nor do I think it would be easy to write a test for this.

Can I assume that you validated this works as expected so I can merge?

Also, if you'd like to see a new release with this fix so it can trickle downstream, you could open another PR with the manifest version update, as I think this repository doesn't allow self-approvals.

Thanks again.

[sfackler]

Yep, I validated it with [patch.crates-io] on an internal thing that was previously failing to build libgit2.

Will follow up with a version bump PR.

[weihanglo]

Would it be better using std::env::join_paths instead of commas to maximize the compatibility?

[Byron]

This could be a great catch!

cargo:include is seemingly unlisted in the docs, maybe I am not looking in the right place though.
With the docs it should be clear what separators can be used - it's surprising that , is support if : or ; would be supported as well. But then again, everything is possible if it's documented somewhere.

[sfackler]

It is the old syntax for

cargo::metadata=KEY=VALUE — Metadata, used by links scripts.

[weihanglo]

cargo:include is arbitrary user-defined cargo:KEY=VALUE, which is superseded by cargo::metadata=KEY=VALUE to have a better extensibility. I am looking at other -sys crate and some of them have the same (not ideal?) pattern.