1 files changed, 15 insertions, 3 deletions
diff --git a/nixpkgs/pkgs/development/python-modules/psycopg2/default.nix b/nixpkgs/pkgs/development/python-modules/psycopg2/default.nix
index bfe33e1ec3ad..43a06e5a9e4d 100644
--- a/nixpkgs/pkgs/development/python-modules/psycopg2/default.nix
+++ b/nixpkgs/pkgs/development/python-modules/psycopg2/default.nix
@@ -8,6 +8,7 @@
 , openssl
 , sphinxHook
 , sphinx-better-theme
+, buildPackages
 }:
 
 buildPythonPackage rec {
@@ -19,20 +20,29 @@ buildPythonPackage rec {
   # c.f. https://github.com/NixOS/nixpkgs/pull/104151#issuecomment-729750892
   disabled = pythonOlder "3.6" || isPyPy;
 
+  outputs = [ "out" "doc" ];
+
   src = fetchPypi {
     inherit pname version;
     hash = "sha256-8AzDW9cRnx/tF7hb0QB4VRlN3iy9jeAauOuxdIdECtg=";
   };
 
-  outputs = [ "out" "doc" ];
+  postPatch = ''
+    # Preferably upstream would not depend on pg_config because config scripts are incompatible with cross-compilation, however postgresql's pc file is lacking information.
+    # some linker flags are added but the linker ignores them because they're incompatible
+    # https://github.com/psycopg/psycopg2/blob/89005ac5b849c6428c05660b23c5a266c96e677d/setup.py
+    substituteInPlace setup.py \
+      --replace "self.pg_config_exe = self.build_ext.pg_config" 'self.pg_config_exe = "${lib.getExe' buildPackages.postgresql "pg_config"}"'
+  '';
 
   nativeBuildInputs = [
-    postgresql
     sphinxHook
     sphinx-better-theme
   ];
 
-  buildInputs = lib.optionals stdenv.isDarwin [
+  buildInputs = [
+    postgresql
+  ] ++ lib.optionals stdenv.isDarwin [
     openssl
   ];
 
@@ -45,6 +55,8 @@ buildPythonPackage rec {
     "psycopg2"
   ];
 
+  disallowedReferences = lib.optionals (stdenv.buildPlatform != stdenv.hostPlatform) [ buildPackages.postgresql ];
+
   meta = with lib; {
     description = "PostgreSQL database adapter for the Python programming language";
     homepage = "https://www.psycopg.org";