Arch isn't affected afaik, as it specifically targeted Debian and RPM. Also, sshd isn't linked against liblzma (or something along those lines). And I hope that's true, because otherwise, I had a backdoor on a public system for over a month.
"These conditions include targeting only x86-64 linux: [...]
Building with gcc and the gnu linker [...]
Running as part of a debian or RPM package build:"