If you create a BE with sysutils/beadm-devel and try to boot into this BE via the loader menu (Option 7), the system will never boot fully. There will be numerous errors like ip6addrctl: fopen: /dev/stdin: No such file or directory swapon: /dev/vtbd0p2: No such file or directory ps: empty file: Invalid argument and you will never see the login prompt. Your only option is to reboot. Superficiously it looks like /dev is missing when booting into an alternative BE. My zfs filesystem layout is standard (created by bsdinstall in the "Auto ZFS" mode). I would be happy to provide any additional info required to debug the problem.
Mike, have you been able to reproduce it?
I can confirm this behavior on 10.3-RELEASE-p7, with sysutils/beadm (as opposed to sysutils/beadm-devel). Boot environments created and activated in user space work just fine, but a boot environment selected from the loader menu (UEFI with vt(4) in my case) will not boot in either single- or multi-user mode.
If I boot into single user mode after selecting an non-default BE in the loader menu, I see a discrepancy: # mount zroot/ROOT/test1 on / (zfs, local, noatime, read-only, nfsv4acls) devfs on /dev (devfs, local, multilabel) # zpool get bootfs zroot NAME PROPERTY VALUE SOURCE zroot bootfs zroot/ROOT/default local # Is it really normal? Looks suspicious to me.
The problem was that / from a different boot environment was being mounted over top of the selected BE, and masking /dev This was fixed by a commit to upstream beadm this morning. The port will be updated soon.
*** This bug has been marked as a duplicate of bug 208601 ***