--- /dev/null
+! xurls -h
+! stderr 'flag provided but not defined'
+stderr 'Usage: xurls'
+! stderr 'help requested' # don't duplicate usage output
+! stderr '-test\.' # don't show the test binary's usage func
+
+! xurls -r -m="whatever"
+stderr 'at the same time'
+
+! xurls -m="bad(regexp"
+stderr 'missing closing \)'