Re: [PATCH v2 1/3] test-lib: allow selecting tests by substring/regex with --run

quoted

@@ -819,9 +821,8 @@ match_test_selector_list () {
                      *)
                              if expr "z$selector" : "z[0-9]*[^0-9]" >/dev/null
                              then
-                                     echo "error: $title: invalid non-numeric in test" \
-                                             "selector: '$orig_selector'" >&2
-                                     exit 1
+                                     echo "$title" | grep -q "$selector" && return
+                                     continue
                              fi

I like that you allow regexes. It's unfortunate that the skip-check
costs us a process in every test. It may not be that big a deal since we
only pay it if you use a non-numeric selector. But I wonder if there's
any reason not to use "expr" here, as well.

If you define the pattern is not regexp but is glob, you can use
case/esac to do this without any forking.

Your expr may well be built-in, though.