bug#79096: du: -x doesn't detect sshfs file system

[Paul Eggert]

Thanks for reporting it. Can you use 'strace' to find out which system 
call is hanging? That would help isolate whether the bug is in 'du' or 
is in the kernel.

At some point we might ask whether you can reproduce the bug with the 
latest stable Coreutils 
<https://ftp.gnu.org/gnu/coreutils/coreutils-9.7.tar.xz> but the 
'strace' is an easy thing to check first.