In reviewing gerrit change 409498, I noticed code for wgExtensionInfoMTime, which is an optimisation to avoid run-time overhead for checking mtimes on all extension.json files.
It seems this optimisation isn't enabled in production. If we don't need it, we should consider removing it (or adding tests for it). Alternatively, if we do need it, we should figure out how we want to enable it, and what it means for our deployment workflow.
Status
- For measured impact, see T187154#5471414 and T233886#5532734.
- For breakdown of ExtensionRegistry bloat/cost, see T187154#5471414.