Hmm, it seems webapp-config doesn't detect invalid groupnames if -p is given the relevant line (1594) in webapp-config reads: if ! $(getent group | grep -q "$G_CONGIG_GID" > /dev/null 2>&1);then "blala not valid" but "getent groups | grep -q $whatever > /dev/null 2>&1" always evaluates to "" (nothing) regardless if the name is valid or not. and if you leave -p out, chown chokes during install. Reproducible: Always Steps to Reproduce: 1. 2. 3. the attached patch resolves this issue and allows for numeric uid/gid. I don't know if it's portable though.
Created attachment 69166 [details, diff] patch against webapp-config 1.11
w-c-1.50.2 should address this issue, please test and reopen if necessary