The Temp Directory variable in ctrl/sbbs.ini is not set by default but Synchronet assumes it is the only user of the directory. Install directory? Provide in an example sbbs.ini file?
Install /opt/syncrhonet/temp directory: add directory to debian/dirs (r183) Add Lintian override for temp directory (r184).
Add example sbbs.ini file with the Temp Directory variable set to /opt/synchronet/temp. (r185)