From 41d5538921e07d291e3f88f6ffaf60d8c2e68daa Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Tue, 21 Mar 2023 08:56:05 -0400
Subject: [PATCH] Fix `maturin build` when using PyPy for the pycddl package

---
 nix/pycddl.nix | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/nix/pycddl.nix b/nix/pycddl.nix
index 703f00595..4c68830d4 100644
--- a/nix/pycddl.nix
+++ b/nix/pycddl.nix
@@ -27,7 +27,7 @@
 #
 # 8. run `nix-build`.  it should succeed.  if it does not, seek assistance.
 #
-{ lib, fetchPypi, buildPythonPackage, rustPlatform }:
+{ lib, fetchPypi, python, buildPythonPackage, rustPlatform }:
 buildPythonPackage rec {
   pname = "pycddl";
   version = "0.4.0";
@@ -38,6 +38,12 @@ buildPythonPackage rec {
     sha256 = "sha256-w0CGbPeiXyS74HqZXyiXhvaAMUaIj5onwjl9gWKAjqY=";
   };
 
+  # Without this, when building for PyPy, `maturin build` seems to fail to
+  # find the interpreter at all and then fails early in the build process with
+  # an error saying "unsupported Python interpreter".  We can easily point
+  # directly at the relevant interpreter, so do that.
+  maturinBuildFlags = [ "--interpreter" python.executable ];
+
   nativeBuildInputs = with rustPlatform; [
     maturinBuildHook
     cargoSetupHook