evolve: don't allow updating or commiting when there is interrupted evolve
We should make things simple in the starting and restrict user from doing things
which can lead to problems.
This is same as the rebase behavior.
# utility to setup pythonpath to point into the tested repository
export SRCDIR=`dirname $TESTDIR`
if [ -n "$PYTHONPATH" ]; then
export HGTEST_ORIG_PYTHONPATH=$PYTHONPATH
export PYTHONPATH=$SRCDIR:$PYTHONPATH
else
export PYTHONPATH=$SRCDIR
fi