Steps to Reproduce:
- Enable the WikiLambda extension (https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/WikiLambda/);
- log the value of $exact (or add a breakpoint) around here or so;
- unbreak this test and run it.
Update: as far as I can tell, this is not a problem with WikiLambda's code (but I am happy to be corrected on that).
$exact will be true-ish even when it's set to false.