While installing a freshly built 12-STABLE (svn rev 354128), errors related to an undefined symbol in /bin/sh began appearing during installworld after that new binary got installed:
===> bin/sh (install)
install -s -o root -g wheel -m 555 -S sh //bin/sh
install -o root -g wheel -m 444 sh.debug //usr/lib/debug/bin/sh.debug
installing DIRS CONFSDIR
install -d -m 0755 -o root -g wheel //etc
installing DIRS CONFSDIR_dot.profile
install -d -m 0755 -o root -g wheel //root
install -o root -g wheel -m 444 sh.1.gz //usr/share/man/man1/
===> bin/sh/tests (install)
ld-elf.so.1: /bin/sh: Undefined symbol "stat@FBSD_1.5"
make: "/etc/make.conf" line 4: warning: "echo /usr/home/elrond/syswork/FreeBSD-work/12-LOCAL/src/bin/sh/tests | sed 's|/usr/ports/.*|/usr/ports|'" returned non-zero status
installing DIRS testsFILESDIR
install -d -m 0755 -o root -g wheel //usr/tests/bin/sh
install -o root -g wheel -m 444 Kyuafile //usr/tests/bin/sh/Kyuafile
It looks I'm not the only one affected as there are some calls for help in the forums such as https://forums.freebsd.org/threads/how-to-resolve-ld-elf-so-1-bin-sh-undefined-symbol-stat-fbsd_1-5.72611/
Strangely enough, /bin/sh looks usable after installation:
# make installworld
root@:/home/elrond/syswork/FreeBSD-work # /bin/sh
I've not yet rebooted and not attempted a mergemaster, I fear that some parts of the installation got borked. I have a pre-install snapshot that I can rollback to in order to install another hopefully fixed build.
mergemaster did complain while populating temproot:
cd: /usr/home/elrond/syswork/FreeBSD-work/12-LOCAL/src/share/zoneinfo/builddir: No such file or directory
make: "/usr/home/elrond/syswork/FreeBSD-work/12-LOCAL/src/share/zoneinfo/Makefile" line 104: warning: "cd /usr/home/elrond/syswork/FreeBSD-work/12-LOCAL/src/share/zoneinfo/builddir && find * -type f | LC_ALL=C sort" returned non-zero status
However this may be unrelated. Apart from these two errors everything else looks to be fine as far as I can tell, including a multi-user reboot.