Source: feynmf Followup-For: Bug #1029439 My current best guess is that this commit line in latex3 that added a dependency on 'hypdoc' to the 'latex/base/doc.sty' file could be the cause - note that GitHub may not expand the 'doc.sty' file by default in some web browsers due to their filtering of large diffs from the user in some cases:
https://github.com/latex3/latex3/commit/015a0593721446d2f5ddfa8d2f5d7c44e9d00fe5#diff-7c335dcde21c7d07e25db3dd241750d7907f90e7ca9b59d4a97309b028e30275R982 I'm not sure why that would be backwards-incompatible with 'feynmf.dtx' though.
