segfault on missing /proc filesystem

Prior to 13.5.1, tor-browser (firefox.real) had been patched/fixed for sandboxes such that missing /proc did not lead to segfault. As of 13.5.1 (and 13.5.3), firefox.real segfaults when it cannot access /proc (/proc/self/maps?).

This is not conducive to strict sandboxes and breaks such setups.

I would be grateful if this could be fixed again such that my current sandbox setup (where /proc is an empty directory) works again for >=13.5.1, as it did in <=13.5.

Please reproduce by attempting to launch firefox.real in a chroot without /proc mounted. Note this may require environment variables to skip launching tor, which I lifted from Whonix (together with using unix sockets).