pkg_config always adds system-wide path to rustc-link-search

[rinon]

Could we get .print_system_libs(false) added to the pkg_config Config? libz-sys is far down the dependency chain from my package and adds /usr/lib to the search path. This means that the linker grabs another library we want to link against from /usr/lib instead of our non-system search path that we add using rustc-link-search.

This is the same basic issue as sfackler/rust-openssl#447 and rust-lang/pkg-config-rs#11

Thanks!

[alexcrichton]

Thanks for the report! I don't think the answer is to not print out -lz, but to just not print out -L /usr/.... Currently I don't think there's an easy way to do that.

[rinon]

If I understand Config.print_system_libs correctly, it just sets PKG_CONFIG_ALLOW_SYSTEM_LIBS=1 for pkg-config, which just disables stripping of -L /usr/lib according to the man page:

PKG_CONFIG_ALLOW_SYSTEM_LIBS
Don't strip -L/usr/lib out of libs

[alexcrichton]

Ok seems like it just needs a PR then!

[joshtriplett]

Merged.