I did a partial system upgrade when installing nginx without upgrading the rest of my Arch system. One of the things it upgraded was libssl.

Turns out systemd depends on that.

Turns out programs won’t start at all if one of their shared libraries is missing.

Turns out that if you write init=bash in the kernel command line, not even Ethernet connections work if systemd isn’t running.

I had to boot off archiso, chroot into my / partition, and run the system upgrade from there.