After upgrading glibc, I could no longer open new terminal tabs, and the
journal contained the following:
Dec 03 15:01:47 jtriplet-mobl2 /usr/lib/gdm3/gdm-x-session[644]: /usr/lib/gnome-terminal/gnome-terminal-server: relocation error: /lib/x86_64-linux-gnu/libnss_files.so.2: symbol __libc_readline_unlocked version GLIBC_PRIVATE not defined in file libc.so.6
gnome-terminal-server needs better handling of failures to start new terminals, and in particular should try re-execing (with children preserved) first. Or alternatively, it should avoid depending on NSS.