> On 6 Nov 2016, at 20:34, Yuriy M. Kaminskiy <yum...@gmail.com> wrote: > > Andreas Henriksson <andr...@fatal.se> writes: > >> It seems /dev/ptmx has incorrect permissions in a pbuilder chroot: >> >> # ls -l /dev/ptmx >> lrwxrwxrwx 1 root root 8 Oct 4 06:43 /dev/ptmx -> pts/ptmx >> # ls -l /dev/pts/ptmx >> c--------- 1 root root 5, 2 Oct 24 14:46 /dev/pts/ptmx >> >> Please compare to what's stated in >> https://www.kernel.org/doc/Documentation/filesystems/devpts.txt >> >> For comparison this is from my regular system: >> $ ls -l /dev/ptmx /dev/pts/ptmx >> crw-rw-rw- 1 root tty 5, 2 okt 24 17:03 /dev/ptmx >> c--------- 1 root root 5, 2 okt 11 12:35 /dev/pts/ptmx >> >> I've hacked up my pbuilder installation and confirmed that appending >> ",ptmxmode=0666" to the /dev/pts mount flags fixes the issue. > > IIRC, it would also need `,newinstance` option by then (otherwise > it will clobber "host system" devpts options).
newinstance seems to be a world of pain, as then it can’t access the TTY for std{in,out,err}. I tried many months ago and couldn’t get it to work, but would love to be proved wrong. James