Due to what I suspect must be either an npins or a lix bug, we get this error when evaluating our configuration on new machines:
โฆ while fetching the input 'git+https://gerrit.wikimedia.org/r/mediawiki/extensions/AdvancedSearch?rev=398c9fa782843d8b3aeaa5ebb1c1b3db35c3382f'
error: Cannot find Git revision '398c9fa782843d8b3aeaa5ebb1c1b3db35c3382f' in ref 'refs/heads/master' of repository 'https://gerrit.wikimedia.org/r/mediawiki/extensions/AdvancedSearch'! Please make sure that the rev exists on the ref you've specified or add allRefs = true; to fetchGit.
Now, this is what I'd expect - because we're not meant to be fetching master of this extension - we're meant to be fetching a branch! By using npins to prefetch all dependencies, we get around this.
Due to a nilla bug, fetching dependencies is required for evaluation anyway - so this isn't too much more of an issue than it would already have been...