diff --git a/var/spack/repos/builtin/packages/python/package.py b/var/spack/repos/builtin/packages/python/package.py index 34b6fb2bad..a3ad52df89 100644 --- a/var/spack/repos/builtin/packages/python/package.py +++ b/var/spack/repos/builtin/packages/python/package.py @@ -511,7 +511,12 @@ def setup_dependent_environment(self, spack_env, run_env, dependent_spec): """Set PYTHONPATH to include the site-packages directory for the extension and any other python extensions it depends on.""" + # If we set PYTHONHOME, we must also ensure that the corresponding + # python is found in the build environment. This to prevent cases + # where a system provided python is run against the standard libraries + # of a Spack built python. See issue #7128 spack_env.set('PYTHONHOME', self.home) + spack_env.prepend_path('PATH', os.path.dirname(self.command.path)) python_paths = [] for d in dependent_spec.traverse(