py3: delete b'' prefix from safehasattr arguments Differential Revision: https://phab.mercurial-scm.org/D7029

destutil: provide hint on rebase+merge for how to specify destination/rev Without a destination specified, rebase and merge attempt to identify a good candidate; this fails if there's too many heads, the heads have a bookmark, or other reasons. Complicating the issue, users may have specified -t, thinking it means target, and are confused when the error message says that they need to specify an explicit rev or explicit destination - they feel like they already have. Differential Revision: https://phab.mercurial-scm.org/D7024

hghave: document format for version feature checks as <name><vers>, no dots I had a bit of a difficult time when attempting to fix a use of `py-38` when trying to figure out what the correct way of specifying the feature was. By having the strings 'py-3*' and 'py3.8' in the hghave.checkvers docstring, I would have had a much easier time of it instead of having to trace exactly what was happening here. Differential Revision: https://phab.mercurial-scm.org/D7023