tests: use --debug on test-clone

tests/test-clone

@@ -29,8 +29,8 b' cat a'
 hg verify
 
 echo
-echo % no update
-hg clone -U . ../c
+echo % no update, with debug option
+hg --debug clone -U . ../c
 cd ../c
 cat a 2>/dev/null || echo "a not present"
 hg verify

tests/test-clone.out

@@ -15,7 +15,8 b' crosschecking files in changesets and ma'
 checking files
 2 files, 11 changesets, 11 total revisions
 
-% no update
+% no update, with debug option
+linked 8 files
 a not present
 checking changesets
 checking manifests