During service start the postfix logs contain an irritating warning message about egrep considered being obsolescent: egrep: warning: egrep is obsolescent; using grep -E Reproducible: Always Steps to Reproduce: 1. systemctl restart postfix 2. journalctl -e 3. Actual Results: Sep 06 23:06:58 systemd[1]: Starting postfix.service - Postfix Mail Transport Agent... Sep 06 23:06:59 postfix[21223]: egrep: warning: egrep is obsolescent; using grep -E Sep 06 23:06:59 postfix/postfix-script[21230]: starting the Postfix mail system Sep 06 23:06:59 postfix/master[21232]: daemon started -- version 3.7.4, configuration /etc/postfix Sep 06 23:06:59 systemd[1]: Started postfix.service - Postfix Mail Transport Agent. NB: the 2nd line is the issue here Expected Results: Sep 06 23:06:58 systemd[1]: Starting postfix.service - Postfix Mail Transport Agent... Sep 06 23:06:59 postfix/postfix-script[21230]: starting the Postfix mail system Sep 06 23:06:59 postfix/master[21232]: daemon started -- version 3.7.4, configuration /etc/postfix Sep 06 23:06:59 systemd[1]: Started postfix.service - Postfix Mail Transport Agent. NB: i.e. the spurious egrep warning is eliminated Besides grepping for egrep in the postfix package files, another way to identify the source of any egrep usage is to use execsnoop. On my system it yields: 11.408 0 egrep 21223 21221 0 /bin/egrep /(saved|incoming|active|defer|deferred|bounce|hold|trace|corrupt|public|private|flush)$ which comes from /usr/libexec/postfix/postfix-script Of course there are basically 2 ways how to fix this: 1) Fix it in postfix, i.e. migrate all postfix scripts from egrep to grep -E 2) Fix it in egrep, i.e. disable that questionable warning and commit to continue supporting egrep, independently of the GNU grep upstream Arguably, that egrep warning and the GNU grep's egrep deprecation warning is rather pointless and a quite superfluous exercise. See also for example this well-written article that looks at it from that angle: https://utcc.utoronto.ca/~cks/space/blog/linux/GNUGrepVersusEcology That article also references: Bug 2188430 - grep-3.8 is incompatible with previous versions of grep for fgrep and egrep https://bugzilla.redhat.com/show_bug.cgi?id=2188430
PS: I'm seeing this with postfix-3.7.4-3.fc38.x86_64 and grep-3.8-3.fc38.x86_64.
It's fixed upstream in postfix-3.8 and the problem shouldn't occur in Fedora 39+. Taking into account it's only "cosmetic" and temporal I am not sure whether it's worth the backport.