doc/automake_migration_tests.txt is in git, but it's also removed by "make distclean", because it matches one of the patterns in the clean_otherdoc target in doc/doc.am. This is a bad combination. If it is to stay, I'd suggest renaming it to simply doc/automake_migration_tests, with no extension.
However, this file documented a build system change that is now essentially complete; the only parts that still seem needed are a couple of notes on possible future work at the bottom which should probably live in the top-level TODO file instead. Should this file simply be removed? It can always be retrieved from the git history if anyone needs it for archaeological purposes. -- Colin Watson [cjwat...@debian.org]