sub include {
  my $file = shift;
  unless (my $return = do $file) {
    my (undef, $callerfile, $callerline) = caller;
    my $from = "included from $callerfile line $callerline";
    die "Couldn't parse $file, $from:\n$@" if $@;
    die "Couldn't do $file, $from: $!" unless defined $return;
    die "Couldn't run $file, $from" unless $return;
  }
}