Comment 9 for bug 1217194

So. Options, in order of (my) preference:

(1) Work out how to package re2 so that it can be pip installed cleanly (https://github.com/axiak/pyre2/issues/27)

(2) background process for regex evaluation, with a watchdog timer

(3) inspect user-supplied regexes to filter out the more obvious degenerate cases

(4) restrict allowed expressions to those expressible by fnmatch

(5) write our own string-matching code

I'll continue working on