my $mergebase = `git-merge-base $branch $ps->{branch}`;
die "Cannot find merge base for $branch and $ps->{branch}" if $?;
chomp $mergebase;
my $mergebase = `git-merge-base $branch $ps->{branch}`;
die "Cannot find merge base for $branch and $ps->{branch}" if $?;
chomp $mergebase;