That is messed up. The prefix redefinition shouldn't be happening if the original prefix setting is NULL.

What version of pkg-config is this? Can you attach the entire --debug output?

It's entirely possible that the --define-prefix behavior is wrong for msys2. That currently defaults to enabled when the pkg-config build host is "*-*-mingw*".

Oh, wait. Isn't msys2 using pkgconf? I don't think this is a pkg-config bug. This would work correctly in pkg-config for 2 reasons:

1. The prefix redefinition only occurs by default if the pc file is in a directory called "pkgconfig". This is a heuristic to try to only do prefix redefinition when operating on installed pc files.

2. The prefix redefinition is skipped if the original prefix is NULL.

Please reopen if this is really pkg-config.

Reopening as msys2 does use pkg-config. I have no pkgconf installed in my msys2 setup (although there is a pkgconf package available).

Please also note that I reproduce the issue when using pkg-config directly on the command line.

$ pkg-config --version
0.29.1

$ pkg-config --libs gstreamer-1.0-uninstalled
-LD:/msys64/mingw64/lib -LD:/M/mingw-w64-gstreamer/src/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -lintl

Note that :
- gstreamer-1.0-uninstalled.pc file is located in a pkgconfig directory
- the gstreamer-1.0-uninstalled.pc file has this line "prefix="
Looks like the original prefix is not NULL but an empty string, which triggers the issue.

Created attachment 125994 [details]
full debug output

Attached full debug output of: 

pkg-config --debug --libs gstreamer-1.0-uninstalled

Created attachment 125995 [details]
full debug output

Created attachment 125996 [details]
full debug output

correct one this time... sorry for the noise.

Created attachment 126012 [details] [review]
Don't override empty prefix setting

If the original prefix setting is empty, skip prepending the redefined
prefix to other variables. This works the same as if the pc file doesn't
have a prefix variable at all.

https://bugs.freedesktop.org/show_bug.cgi?id=97453-empty

Right. I was thinking that empty and not set would be handled the same in the code, but that was wrong. Can you try attachment 126012 [details] [review]?

With the patch there is one failed test:

../pkg-config.exe --cflags public-dep :
'-I/sysroot/public-dep/include' != '-ID:/msys64//sysroot/public-dep/include'
FAIL: check-sysroot
...
1 of 28 tests failed


There is also a minor issue when applying the patch:

patching file check/Makefile.am
Hunk #1 succeeded at 98 (offset -1 lines).
patching file check/check-relocatable
patching file check/pkgconfig/empty-prefix.pc
patching file parse.c
patch unexpectedly ends in middle of line

but the patch is applied fine nonetheless.

Oddly, it fails in the same manner without the patch.

When you say fails in the same manner, are you referring to the check-sysroot test? If so, I'm not surprised. This patch shouldn't affect that behavior. The test may not be looking for the right result on msys2. I wouldn't worry about that one.

Does the patch fix your gstreamer case?

Yes, the build fails the check-sysroot test with and withour your patch.

Hacking line 12 of the check-sysroot file so it leaves the root variable empty allows the build to complete successfully.

And with this version of pkg-config, gstreamer 1.8.2 still fails.

../../../libtool: line 7537: cd: ../../D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs: No such file or directory
libtool:   error: cannot determine absolute directory name of '../../D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs'


I don't have the spurious prefix prepended anymore. But I have a ../.. prepended... Don't know where that one comes from (and I think it was there too before your fix).

Ok. I am bit lost atm and will need to do more research.

The step that fails when compiling gstreamer is related to g-ir-scanner:

GstBase-1.0.gir: $(INTROSPECTION_SCANNER) libgstbase-1.0.la
	$(AM_V_GEN)PKG_CONFIG_PATH="$(GST_PKG_CONFIG_PATH)" GI_SCANNER_DISABLE_CACHE=yes\
		GST_PLUGIN_SYSTEM_PATH_1_0="" GST_PLUGIN_PATH_1_0="" GST_REGISTRY_UPDATE=no \
		$(INTROSPECTION_SCANNER) -v --namespace GstBase \
		--nsversion=1.0 \
		--warn-all \
		--identifier-prefix=Gst \
		--symbol-prefix=gst \
		-I$(top_srcdir) \
		-I$(top_srcdir)/libs \
		-I$(top_builddir) \
		-I$(top_builddir)/libs \
		--c-include "gst/base/base.h" \
		--add-include-path=$(top_builddir)/gst \
		--library-path=$(top_builddir)/gst \
		--library=libgstbase-1.0.la \
		--include=Gst-1.0 \
		--libtool="${LIBTOOL}" \
		--pkg gstreamer-1.0 \
		--pkg-export gstreamer-base-1.0 \
		--add-init-section="$(INTROSPECTION_INIT)" \
		--output $@ \
		$(gir_headers) \
		$(gir_sources)

I don't know what it does with --pkg arguments (i.e. if and how it uses pkg-config).

$ export PKG_CONFIG_PATH="../../../pkgconfig:/mingw64/lib/pkgconfig"

$ pkg-config --libs gstreamer-1.0-uninstalled
-L../../D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs -LD:/msys64/mingw64/lib -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -lintl

$ pkg-config --dont-define-prefix --libs gstreamer-1.0-uninstalled
-L/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -lintl



With gstreamer-1.0-uninstalled.pc:

# the standard variables don't make sense for an uninstalled copy
prefix=
exec_prefix=
libdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs
# includedir is builddir because it is used to find gstconfig.h in places
includedir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32
toolsdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/tools
pluginsdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32
girdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst
completionsdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/data/completions
helpersdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/libs/gst/helpers
typelibdir=/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst

Name: GStreamer Uninstalled
Description: Streaming media framework, Not Installed
Version: 1.8.2
Requires: glib-2.0, gobject-2.0
Requires.private: gmodule-no-export-2.0
Libs: -L${libdir} -lgstreamer-1.0
Cflags: -I/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/../gstreamer-1.8.2 -I/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/../gstreamer-1.8.2/libs -I/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32 -I/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/libs



If I force the value used in Libs (without using ${libdir} then I get the correct result with and without the --dont-define-prefix option.

$ pkg-config --libs gstreamer-1.0-uninstalled
-L/D/M/mingw-w64-gstreamer/src/build-x86_64-w64-mingw32/gst/.libs -LD:/msys64/mingw64/lib -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -lintl



What is strange is that msys2 as a patch to force g-ir-introspection to use the --dont-define-prefix flag (https://github.com/Alexpux/MINGW-packages/blob/master/mingw-w64-gobject-introspection/0022-change-pkg-config-invocations.mingw.patch). Seems to be broken somehow.

PS : message just above is with the patched pkg-config.

Seems like the patched version is installed only for msys2 shell and not mingw64 shell. Duh!

gstreamer compiles fine with the patched pkg-config. Thanks!

Hi,

What is the release policy/frequency of pkg-config ?

Should I wait for a new release with a fix for this issue or proceed to patch msys2 ?

Pushed in commit bbbdab4 - https://cgit.freedesktop.org/pkg-config/commit/?id=bbbdab4.

I do the releases basically when I have time :) There are a couple more fixes I'd like to get in for the next release, so it'll probably be a couple more weeks. If you need this now, I'd add the patch to msys2. Since it's a one liner, it will be easy to spot that it's not needed when updating.