if (quilt_could_gbp($target,$unapplied,$oldtiptree)) {
print STDERR <<END;
$us: Tree looks like a patches-unapplied git branch.
-$us: Maybe you forgot --quilt=gbp (aka --quilt=apply) ?
+$us: Maybe you forgot --quilt=gbp (or --quilt=apply) ?
END
}
fail "quilt fixup naive history linearisation failed.\n".