They suggested raising the issue in the Debian package system as the chroot comes from the upstream Debian package. �And I came across this bug.

I was able to figure out all of the configuration files necessary in the chroot as I have several other services configured in a similar way, but the lack of the /var/tmp directory really took some digging to figure out. �Would it be possible to include the creation of such a directory in the package installation?

Short of that, is there a way to configure the gssapi library to use a different ___location for the credential cache that does exist in the current postfix chroot structure?