While trying to rebuild my site to change the location of the tags, I get a no space left error:

generating wrappers..
/home/b-charles-plessy-org/public_html/ikiwiki.cgi.c:123: fatal error: error writing to /tmp/cc7FTrCq.s: No space left on device
compilation terminated.
failed to compile /home/b-charles-plessy-org/public_html/ikiwiki.cgi.c

Error: ikiwiki -setup /home/b-charles-plessy-org/ikiwiki.setup -rebuild -v exited nonzero (256). Discarding setup changes.

I've fixed the immediate problem and we will be taking steps (notably, use of per-site temporary directories, and better monitoring) to ensure it does not occur again.

As well as affecting changes to the configuration of your site, this could have blocked uploading of attachments. Creating new sites could potentially have been affected, but does not seem to have been. All other actions (like editing pages, git pushes, etc), appear to have been unaffected.

Update: Per-site temp directories are now used, so unrelated partitions filling up can no longer affect your site. done --Joey

Update: We've improved our monitoring, so we should react better to this type of problem in the future. Although we are just 2 guys and are sometimes both asleep. :) Thanks very much for reporting this, Charles. --Joey

Here are the changes I wanted to make:

format plugin: po