evolve: fix error in builddependencies When MultipleSuccessorsError was raised, we were still running the code below to add the dependency if succ was not None from a previous iteration. This bug was harmless because dependencies and rdependencies are sets but it makes the code clearer this way.

syntax: re
/figures/[^/]+\.png$
^docs/build/
^docs/html/
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
\.err$
^tests/easy_run.sh$
^build/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$