--- a/tests/test-debugextensions.t	Wed Apr 04 12:16:50 2018 -0700
+++ b/tests/test-debugextensions.t	Wed Apr 04 13:21:34 2018 -0700
@@ -1,4 +1,6 @@
+#if no-extraextensions
   $ hg debugextensions
+#endif
 
   $ debugpath=`pwd`/extwithoutinfos.py
 
@@ -19,6 +21,10 @@
   > ext2 = `pwd`/extwithinfos.py
   > EOF
 
+  $ for extension in $HGTESTEXTRAEXTENSIONS; do
+  >     echo "$extension=!" >> $HGRCPATH
+  > done
+
   $ hg debugextensions
   ext1 (untested!)
   ext2 (3.2.1!)