The page https://www.mediawiki.org/wiki/Extension:VipsScaler links to https://phabricator.wikimedia.org/diffusion/EVIP/browse/01f476f7bda68aa2d3718be14fa642c2cb26c251/VipsScaler.php#L60 however this shows:
Ref "01f476f7bda68aa2d3718be14fa642c2cb26c251" does not exist in this repository.
That statement is a lie. It seems the browse feature doesn't support SHA1 pointers in the url segment (only branch names, such as "master", not 01f476f7bda68aa2d3718be14fa642c2cb26c251 or HEAD).
But, it is capable of viewing blobs from a specific point in history, just via a different url syntax:
Not sure why, and it involves including a strange "master" in the url as well. Not sure if this is result of a configuration issue or if it is supposed to work like that. If it is, we should update urls and templates and such that currently assume the former url structure (which presumably worked in previous versions of Phabricator Diffusion).