evolve: abort if deciding resolution parent is ambiguous While solving content-divergence, it could be hard to decide which cset should be treated as a resolution parent if there are multiple successors of divergent cset. i.e split case. But we are planning to make some update in handling this split case: 1) consider highest one if all splitted csets are in a single topological branch 2) still need to decide if 1) doesn't apply

#require test-repo pyflakes

Copied from Mercurial core (60ee2593a270)

  $ cd "`dirname "$TESTDIR"`"

run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)

  $ hg locate -I 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
  > | xargs pyflakes 2>/dev/null