Package: jq Followup-For: Bug #908393 I figured it out - my ldd shows libjq in /usr/local/lib and that was being loaded by the binary instead of Debian libjq. Doing "rm /usr/local/lib/libjq*" fixed the issue.
This is from a machine that I don't log into often and must have been left over from a time I compiled my own jq to get round some bugs and never cleaned it up properly. I'll close this bug out, sorry for the wild goose chase.