with app-emulation/lxc-2.0.8 i get lxc-start: start.c: lxc_spawn: 1182 Failed to set up id mapping. with app-emulation/lxc-2.0.7 everything works fine.
I was also getting a similar error with version 2.0.8. I found a work-around here: https://github.com/lxc/lxc/issues/1555#issuecomment-301254419 Upstream seems to indicate we are installing newuidmap and newgidmap with incorrect permissions. Lxc 2.0.8 works fine after I run: sudo chmod 04755 /usr/bin/newuidmap sudo chmod 04755 /usr/bin/newgidmap
Do you still have the same problems in newer LXC versions? Things have been working fine here and newuidmap/newgidmap have 4711 perms on my system.