From f1a58aba151e59c4a5c438c501663944d608011f Mon Sep 17 00:00:00 2001
From: Thomas Tuegel <ttuegel@mailbox.org>
Date: Thu, 16 Jul 2020 10:41:32 -0500
Subject: [PATCH] exiv2: fix CMake export paths

---
 pkgs/development/libraries/exiv2/default.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/exiv2/default.nix b/pkgs/development/libraries/exiv2/default.nix
index 8a6dfd1983ef..02d3f1da3e69 100644
--- a/pkgs/development/libraries/exiv2/default.nix
+++ b/pkgs/development/libraries/exiv2/default.nix
@@ -98,7 +98,7 @@ stdenv.mkDerivation rec {
     (cd ../tests/ && python3 runner.py)
   '';
 
-  # With cmake we have to enable samples or there won't be
+  # With CMake we have to enable samples or there won't be
   # a tests target. This removes them.
   postInstall = ''
     ( cd "$out/bin"
@@ -108,6 +108,14 @@ stdenv.mkDerivation rec {
     )
   '';
 
+  # Fix CMake export paths.
+  postFixup = ''
+    sed -i "$dev/lib/cmake/exiv2/exiv2Config.cmake" \
+        -e "/INTERFACE_INCLUDE_DIRECTORIES/ s@\''${_IMPORT_PREFIX}@$dev@" \
+        -e "/Compute the installation prefix/ a set(_IMPORT_PREFIX \"$out\")" \
+        -e "/^get_filename_component(_IMPORT_PREFIX/ d"
+  '';
+
   enableParallelBuilding = true;
 
   meta = with stdenv.lib; {