I suspected meld needed them to be also writable. However, it does say
Could not read file (notice "read"); plus then the implication would be that they are writable for root, because there was no such error for root.
~$ diff <(echo foo) <(echo bar) 1c1 < foo --- > bar ~$ meld <(echo foo) <(echo bar) # not working, see comment below ~$ sudo -s ~# meld <(echo foo) <(echo bar) # works just fine
The first one returns
Could not read file and
[Errno 2] No such file or directory: '/dev/fd/63'.
What do you suspect is the reason for this behavior?
Unprivileged user above, root below.