[arch-dev-public] /dev/shm permissions and building in chroot

[Allan McRae]

Hi,

I have been tracking down a python3 bug and it turns out to be caused by 
our chroot building.  Essentially the permissions of /dev/shm are 
different in the chroot than on the system:

allan at mugen /home/arch/chroot/stable-i686/copy/dev
 > ls -ld shm
drwxr-xr-x 2 root root 40 Jul 12 15:16 shm

allan at mugen /dev
 > ls -ld shm
drwxrwxrwt 2 root root 40 Aug 14 10:23 shm

So when configure scripts try to test for POSIX semaphores by writing in 
that directory, they fail.

Looking at the relevant line in mkarchroot:
mount -o bind /dev "${working_dir}/dev"

Doing that manually show the same issue.   Should we add

chmod 1777 "${working_dir}/dev/shm"

after the mount?  It fixes my issue but feels hackish.  Any other 
suggestions?

Allan