discourse/update.py: use nix-instantiate

The interface of `nix eval` is not stable across versions of nix that
are currently in the wild, so use the older nix-instantiate command
instead.

1 files changed, 1 insertions, 1 deletions

diff --git a/pkgs/servers/web-apps/discourse/update.py b/pkgs/servers/web-apps/discourse/update.py
index 8352ac09f367a..ffdff7bc06a15 100755
--- a/pkgs/servers/web-apps/discourse/update.py
+++ b/pkgs/servers/web-apps/discourse/update.py
@@ -79,7 +79,7 @@ def _call_nix_update(pkg, version):
 def _nix_eval(expr: str):
     nixpkgs_path = Path(__file__).parent / '../../../../'
     try:
-        output = subprocess.check_output(['nix', 'eval', '--json', f'(with import {nixpkgs_path} {{}}; {expr})'], text=True)
+        output = subprocess.check_output(['nix-instantiate', '--strict', '--json', '--eval', '-E', f'(with import {nixpkgs_path} {{}}; {expr})'], text=True)
     except subprocess.CalledProcessError:
         return None
     return json.loads(output)