python.pkgs.pkgconfig: hardcode path to pkg-config

pkgs/development/python-modules/pkgconfig/default.nix

@@ -11,12 +11,17 @@ buildPythonPackage rec {
 
   checkInputs = [ nose ];
 
-  propagatedBuildInputs = [ pkgconfig ];
+  nativeBuildInputs = [ pkgconfig ];
 
   checkPhase = ''
     nosetests
   '';
 
+  patches = [ ./executable.patch ];
+  postPatch = ''
+    substituteInPlace pkgconfig/pkgconfig.py --replace 'PKG_CONFIG_EXE = "pkg-config"' 'PKG_CONFIG_EXE = "${pkgconfig}/bin/pkg-config"'
+  '';
+
   meta = with lib; {
     description = "Interface Python with pkg-config";
     homepage = https://github.com/matze/pkgconfig;

pkgs/development/python-modules/pkgconfig/executable.patch

@@ -0,0 +1,38 @@
+commit d8e0bac0c0d831510683939ec7a7b5bd72192423
+Author: Frederik Rietdijk <fridh@fridh.nl>
+Date:   Sat Jan 5 11:38:28 2019 +0100
+
+    Have a top-level attribute for the executable
+
+diff --git a/pkgconfig/pkgconfig.py b/pkgconfig/pkgconfig.py
+index 3deb97f..e7c5561 100644
+--- a/pkgconfig/pkgconfig.py
++++ b/pkgconfig/pkgconfig.py
+@@ -30,6 +30,9 @@ from functools import wraps
+ from subprocess import call, PIPE, Popen
+ 
+ 
++PKG_CONFIG_EXE = "pkg-config"
++
++
+ def _compare_versions(v1, v2):
+     """
+     Compare two version strings and return -1, 0 or 1 depending on the equality
+@@ -65,7 +68,7 @@ def _convert_error(func):
+ 
+ @_convert_error
+ def _query(package, *options):
+-    pkg_config_exe = os.environ.get('PKG_CONFIG', None) or 'pkg-config'
++    pkg_config_exe = os.environ.get('PKG_CONFIG', None) or PKG_CONFIG_EXE
+     cmd = '{0} {1} {2}'.format(pkg_config_exe, ' '.join(options), package)
+     proc = Popen(shlex.split(cmd), stdout=PIPE, stderr=PIPE)
+     out, err = proc.communicate()
+@@ -84,7 +87,7 @@ def exists(package):
+ 
+     If ``pkg-config`` not on path, raises ``EnvironmentError``.
+     """
+-    pkg_config_exe = os.environ.get('PKG_CONFIG', None) or 'pkg-config'
++    pkg_config_exe = os.environ.get('PKG_CONFIG', None) or PKG_CONFIG_EXE
+     cmd = '{0} --exists {1}'.format(pkg_config_exe, package).split()
+     return call(cmd) == 0
+