--- a/tests/test-doctest.py	Sat Oct 26 13:56:46 2024 -0400
+++ b/tests/test-doctest.py	Mon Oct 07 12:08:48 2024 +0100
@@ -72,9 +72,13 @@
     sys.exit(0)
 
 files = subprocess.check_output(
-    "HGRCPATH=/dev/null . helpers-testrepo.sh; testrepohg files --print0 \"%s\""
-    % fileset,
-    shell=True,
+    [
+        "sh",
+        "-c",
+        "set -e; . helpers-testrepo.sh; testrepohg files --print0 \"%s\""
+        % fileset,
+    ],
+    shell=False,
     cwd=cwd,
 ).split(b'\0')