The gitian build fails with the installed Ubuntu package lxc 3.0.3-0ubuntu1~18.04.1 (bionic-updates):
...
--- Building for bionic amd64 ---
Stopping target if it is up
Making a new image copy
lxc-execute: gitian: start.c: print_top_failing_dir: 125 No such file or directory - Could not access /var/lib/lxc. Please grant it x access, or add an ACL for the container root
lxc-execute: gitian: sync.c: __sync_wait: 62 An error occurred in another process (expected sequence number 3)
lxc-execute: gitian: start.c: __lxc_start: 1939 Failed to spawn container "gitian"
lxc-execute: gitian: tools/lxc_execute.c: main: 245 Failed run an application inside container
Traceback (most recent call last):
6: from bin/gbuild:302:in `<main>'
5: from bin/gbuild:302:in `each'
4: from bin/gbuild:304:in `block in <main>'
3: from bin/gbuild:304:in `each'
2: from bin/gbuild:309:in `block (2 levels) in <main>'
1: from bin/gbuild:58:in `build_one_configuration'
bin/gbuild:21:in `system!': failed to run make-clean-vm --suite bionic --arch amd64 (RuntimeError)
...
It works as expected with lxc 3.0.1-0ubuntu1~18.04.2 (bionic-security).
Digging to the root of the issue...