[Reproducible-builds] Bug#797781: diffoscope does not seem to work with schroot

[Santiago Vila]

Package: diffoscope
Version: 31

Greetings. I'm running jessie with several chroots created with
schroot. As a normal user, I do this:

schroot -c sid
diffoscope some.deb someother.deb

and this is the result:

CRITICAL /dev/shm is not available or not on a tmpfs. Unable to create semaphore.

I believe such error is not supposed to happen.

Thanks.