From 3c20057d0cbbbed453a692d4dd4589d865808024 Mon Sep 17 00:00:00 2001
From: Liliana Marie Prikler <liliana.prikler@gmail.com>
Date: Sat, 29 Jan 2022 10:44:44 +0100
Subject: [PATCH] Add pkg-config fallback for locating ffmpeg.

Audacity >=3.1.0 no longer links against ffmpeg, but instead dynamically loads
it.  This dynamic loading mechanism fails to properly locate libraries outside
of LD_LIBRARY_PATH.

See <https://issues.guix.gnu.org/53591>.

Bugs-added-by: Marius Bakke <marius@gnu.org>

diff --git a/libraries/lib-ffmpeg-support/CMakeLists.txt b/libraries/lib-ffmpeg-support/CMakeLists.txt
index b8803a1f5..f86559cca 100644
--- a/modules/mod-ffmpeg/lib-ffmpeg-support/CMakeLists.txt
+++ b/modules/mod-ffmpeg/lib-ffmpeg-support/CMakeLists.txt
@@ -1,5 +1,7 @@

 if (${_OPT}use_ffmpeg)
+   pkg_check_modules(FFMPEG libavcodec libavformat libavutil)
+
    set( SOURCES
       FFmpegTypes.h

@@ -107,6 +109,12 @@ if (${_OPT}use_ffmpeg)
       list(APPEND DEFINITIONS PRIVATE _DARWIN_C_SOURCE )
    endif()

+   if (FFMPEG_FOUND)
+      pkg_get_variable(LIBAVCODEC_LIBDIR libavcodec libdir)
+      list(APPEND DEFINITIONS PRIVATE
+                  "-DFFMPEG_PC_LIBDIR=\"${LIBAVCODEC_LIBDIR}\"")
+   endif()
+
    audacity_library( lib-ffmpeg-support "${SOURCES}" "${LIBRARIES}"
       "${DEFINITIONS}" ""
    )
diff --git a/libraries/lib-ffmpeg-support/FFmpegFunctions.cpp b/libraries/lib-ffmpeg-support/FFmpegFunctions.cpp
index 55d6f676b..46640ef83 100644
--- a/modules/mod-ffmpeg/lib-ffmpeg-support/FFmpegFunctions.cpp
+++ b/modules/mod-ffmpeg/lib-ffmpeg-support/FFmpegFunctions.cpp
@@ -246,6 +246,18 @@ struct FFmpegFunctions::Private final
       if (library->IsLoaded())
          return library;

+#if defined(FFMPEG_PC_LIBDIR)
+      {
+         static const wxString libdir{FFMPEG_PC_LIBDIR};
+         const wxString fullName = wxFileName(libdir, libraryName).GetFullPath();
+
+         auto library = std::make_shared<wxDynamicLibrary>(fullName);
+
+         if (library->IsLoaded())
+            return library;
+      }
+#endif
+
       return {};
    }
 };
311a68'>root</a>/<a href='/guix/log/etc?id=1d9169847886985f2b45fddc458d92244f311a68'>etc</a>/<a href='/guix/log/etc/system-tests.scm?id=1d9169847886985f2b45fddc458d92244f311a68'>system-tests.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/system-tests.scm?id=1d9169847886985f2b45fddc458d92244f311a68&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-08-09 15:16:06 +0200'>2022-08-09</span></td><td><a href='/guix/commit/etc/system-tests.scm?id=5bce4c82422de6beb3ce6120ba1592be898c2b72'>build-system: Add 'channel-build-system'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/ci.scm (channel-build-system, channel-source-&gt;package): Remove.
* gnu/packages/package-management.scm (channel-source-&gt;package): New
procedure, moved from (gnu ci).
* guix/build-system/channel.scm: New file, with code moved from (gnu ci).
* doc/guix.texi (Build Systems): Document it.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-07-10 23:57:14 +0200'>2022-07-10</span></td><td><a href='/guix/commit/etc/system-tests.scm?id=9fdc4b6c283c5aa5cf10205d87fb2c58b829b9d0'>monads: Add 'mparameterize'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/system-tests.scm (mparameterize): Move to...
* guix/monads.scm (mparameterize): ... here.
* tests/monads.scm ("mparameterize"): New test.
* .dir-locals.el (c-mode): Add it.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-04-11 00:25:33 +0200'>2022-04-11</span></td><td><a href='/guix/commit/etc/system-tests.scm?id=dbde386794cb5f4773b94a20ef585ca0f881544a'>tests: System tests really parameterize 'current-guix-package'.</a><span class='msg-avail'>...<span class='msg-tooltip'>Until now, 'current-guix-package' was parameterized in the wrong
context.  Thus, 'current-guix' would end up building a variant of the
'guix' package instead of the package returned by
'channel-source-&gt;package', which is much less expensive to build.

* etc/system-tests.scm (mparameterize): New macro.
(tests-for-current-guix): Change the 'value' field of each &lt;system-test&gt;
record to parameterize 'current-guix-package' for good.
</span></span></td><td>Ludovic Courtès</td></tr>