Comment by Max Liberman (JIRA)

I'm running into this issue as well, in my case with the cairo library. It looks like the problem in both cases is that the gobject-2.0 library's .pc file has an absolute path in its Requires.private field, which SPM does not currently support.

$ cat $(brew --prefix)/opt/glib/lib/pkgconfig/gobject-2.0.pc
prefix=/usr/local/Cellar/glib/2.64.3
libdir=${prefix}/lib
includedir=${prefix}/include

Name: GObject
Description: GLib Type, Object, Parameter and Signal Library
Version: 2.64.3
Requires: glib-2.0
Requires.private: /usr/local/opt/libffi/lib/pkgconfig/libffi.pc >=  3.0.0
Libs: -L${libdir} -lgobject-2.0
Libs.private: -lintl
Cflags:-I${includedir}

Comment by Max Liberman (JIRA)

I opened a PR here.

Comment by Serhii Mumriak (JIRA)

mliberman (JIRA User) oh my god, thank you so much! can i ask how did you find the underlying problem? I was thinking about debugging swiftpm itself, but it's not really possible which i tried to find help for here: https://forums.swift.org/t/is-there-a-way-to-debug-swift-package-manager-in-xcode/37185/5

Comment by Max Liberman (JIRA)

PALKOVNIK (JIRA User) I tracked down the warning message ("you may be able to install...") to here. I discovered that PkgConfig is part of the SwiftToolsSupport library (specifically, the TSCUtility module), so I created a new executable Swift package that pulled in that dependency, and was able to debug the PkgConfig constructor that way.

Comment by Max Liberman (JIRA)

PALKOVNIK (JIRA User) by the way, as a local workaround, you can just change the Requires.private line in gobject-2.0.pc to:

Requires.private: libffi >=  3.0.0

The file should be located at:

$(brew --prefix)/opt/glib/lib/pkgconfig/gobject-2.0.pc

Comment by Serhii Mumriak (JIRA)

mliberman (JIRA User) yea, I was also going thru `TSCUtility`, did not know about the `Requires.private` in pkg-config (I mean I don't know much about it at all). Also thanks for the workaround, I'll try it today 🙂

Comment by Serhii Mumriak (JIRA)

mliberman (JIRA User) I tried that workaround with changing the absolute path to just `libffi >= 3.0.0` and the issue is still there. I assume that's the one you've fixed is a different one.

UPD. oops, did not remove the file extension and it works correctly. Thanks for fix!

Comment by Tobias H (JIRA)

Hello, I think I've also encountered a similar, maybe the same problem. I think this issue has actually been fixed in the `main` branch of `apple/swift-tools-support-core`:

See my post here: https://forums.swift.org/t/possible-bug-regression-with-regards-to-pc-files/42306