severity 1053444 grave thanks See e.g. https://buildd.debian.org/status/fetch.php?pkg=libx11&arch=all&ver=2%3A1.8.7-1&stamp=1696420352&raw=0
quilt pop exits 2 if it has nothing to do (https://sources.debian.org/src/quilt/0.67%2Breally0.67-1/quilt/pop.in/#L246), so that should be expected and not an error for dh_quilt_unpatch.