Gerrit has an excellent search system that can find any commit by its SHA1 hash. By default it will redirect from the search to the changeset (merge request), as it does with almost anything, redirects. Which is nice.
Also nice is that when a commit is merged to another branch, searching for the SHA1 hash will show a simple search results list with both changesets that requested a merge of that commit to a certain branch.
Anyway, https://gerrit.wikimedia.org/r/#/c/7265/ mentions 2 SHA1s. Would be nice if those were auto-linked to gerrit's search.
gitweb does link them:
Regex: /\b([a-f0-9]{40})\b/
Link: https://gerrit.wikimedia.org/r/#q,$1,n,z
(including the ",n,z" afterwards, not sure why Gerrit needs it, otherwise it doesn't perform the search)
Version: unspecified
Severity: normal