From f0a86e6d119877f47452a790157def800aef5a61 Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Mon, 2 Sep 2024 15:31:13 +0200
Subject: [PATCH 1/2] libunwind.meta.pkgConfigModules: init

This will allow packages like gstreamer that need to find libunwind
via pkg-config to check whether the libunwind they've been given has
the modules they expect.
---
 .../development/libraries/libunwind/default.nix | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/libraries/libunwind/default.nix b/pkgs/development/libraries/libunwind/default.nix
index 1f7074866d589..6f491a5c527f0 100644
--- a/pkgs/development/libraries/libunwind/default.nix
+++ b/pkgs/development/libraries/libunwind/default.nix
@@ -1,13 +1,16 @@
-{ stdenv, lib, fetchpatch, fetchFromGitHub, autoreconfHook, xz, buildPackages }:
+{ stdenv, lib, fetchpatch, fetchFromGitHub, autoreconfHook, buildPackages
+, xz
+, testers
+}:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "libunwind";
   version = "1.8.1";
 
   src = fetchFromGitHub {
     owner = "libunwind";
     repo = "libunwind";
-    rev = "v${version}";
+    rev = "v${finalAttrs.version}";
     hash = "sha256-rCFBHs6rCSnp5FEwbUR5veNNTqSQpFblAv8ebSPX0qE=";
   };
 
@@ -50,12 +53,18 @@ stdenv.mkDerivation rec {
 
   doCheck = false; # fails
 
+  passthru.tests.pkg-config = testers.hasPkgConfigModules {
+    package = finalAttrs.finalPackage;
+    versionCheck = true;
+  };
+
   meta = with lib; {
     homepage = "https://www.nongnu.org/libunwind";
     description = "Portable and efficient API to determine the call-chain of a program";
     maintainers = with maintainers; [ orivej ];
+    pkgConfigModules = [ "libunwind" "libunwind-coredump" "libunwind-generic" "libunwind-ptrace" "libunwind-setjmp" ];
     # https://github.com/libunwind/libunwind#libunwind
     platforms = [ "aarch64-linux" "armv5tel-linux" "armv6l-linux" "armv7a-linux" "armv7l-linux" "i686-freebsd" "i686-linux" "loongarch64-linux" "mips64el-linux" "mipsel-linux" "powerpc64-linux" "powerpc64le-linux" "riscv64-linux" "s390x-linux" "x86_64-freebsd" "x86_64-linux" "x86_64-solaris" ];
     license = licenses.mit;
   };
-}
+})

From 52b0b4ef3d2b1b6a76f97d0c8c50def5640ab7c1 Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Mon, 2 Sep 2024 15:33:23 +0200
Subject: [PATCH 2/2] gst_all_1.gstreamer: use a better libunwind check

Checking for Darwin didn't take into account that we also use a
libunwind implementation without pkg-config on riscv32-linux.  Fix by
checking for the presence of the pkg-config file required directly,
rather than by using platform as a proxy.
---
 pkgs/development/libraries/gstreamer/core/default.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/libraries/gstreamer/core/default.nix b/pkgs/development/libraries/gstreamer/core/default.nix
index e8f873555d70b..d1094cfc8794c 100644
--- a/pkgs/development/libraries/gstreamer/core/default.nix
+++ b/pkgs/development/libraries/gstreamer/core/default.nix
@@ -21,8 +21,9 @@
 , buildPackages
 , withIntrospection ? lib.meta.availableOn stdenv.hostPlatform gobject-introspection && stdenv.hostPlatform.emulatorAvailable buildPackages
 , libunwind
-# darwin.libunwind doesn't have pkg-config definitions so meson doesn't detect it.
-, withLibunwind ? !stdenv.isDarwin && lib.meta.availableOn stdenv.hostPlatform libunwind
+, withLibunwind ?
+  lib.meta.availableOn stdenv.hostPlatform libunwind &&
+    lib.elem "libunwind" libunwind.meta.pkgConfigModules or []
 # Checks meson.is_cross_build(), so even canExecute isn't enough.
 , enableDocumentation ? stdenv.hostPlatform == stdenv.buildPlatform, hotdoc
 }: