GNU GAS protip: if you need to introduce a local label in a macro "hygienically", you can just use \@ as a numbered label. For example:
.macro car cons, result
cmp \cons, 0
beq \@f // Don't read anything if `\cons' is `nil'.
ldr \result, [\cons, 0]
\@: csel \result, \result, xzr, ne // If \cons is `nil', the answer will be `nil'.
Mastodon is a server for a federated social network: everyone can run a server if they want to, including me. So this is a Mastodon server for me (Vierkantor) and my friends.