Custom build should allow "-F" and "-framework" flags

[jonasp]

On OS X we need framework directories -F and framework names -framework to build dependencies.

Here is for example the Qt Qml library

$ pkg-config --libs Qt5Qml
-F/usr/local/Cellar/qt5/5.4.0/lib -framework QtQml -F/usr/local/Cellar/qt5/5.4.0/lib -framework QtNetwork -F/usr/local/Cellar/qt5/5.4.0/lib -framework QtCore

Cargo explicitly allows only -L and -l flags.

[alexcrichton]

The Rust compiler doesn't use the same -F and -framework flags that the linkers use, it actually uses -l framework=foo and -L native=foo for -framework and -F, respectively. Which is all to say that this should be possible today!

[jonasp]

This is great, -l framework=foo works perfectly but -L native=foo does not give -F but -L. Any ideas why?

Sidenote: if this works pkg-build-rs still needs to accept the -F and -framework flags and translate them accordingly. Do you want me to open a separate issue at the pkg-build-rs issue tracker?

[alexcrichton]

Gah, right! Looks like two issues need to be opened:

1. An issue on rust-lang/rust for accepting -L framework=foo and translating that to -F.
2. An issue on pkg-config-rs to accept -F and -framework and translate accordingly.

[jonasp]

There is already rust-lang/rust/#20259 so I won't open a new one. I'll just add a note on the -L framework=foo solution.

[alexcrichton]

Ok, thanks @jonasp!