I've made some headway in figuring out whats going on.
I've compared the qemu and lxc backends for autopkgtest and found two very
notable differences.
1) The qemu one installs shared-mime-info. lxc doesn't.
2) Apparmor rules in lxc lead to namespace failures.
Here's how I compared the two.
Launching qemu like this:
#autopkgtest --apt-upgrade --add-apt-release=unstable
--pin-packages=unstable=src:fwupd,src:libxmlb fwupd -- qemu
autopkgtest-testing.img
Launching lxc like this
# autopkgtest --apt-upgrade --add-apt-release=unstable
--pin-packages=unstable=src:fwupd,src:libxmlb fwupd -- lxc autopkgtest-testing
shared-mime-info
----------------------
shared-mime-info gets install in qemu but not in lxc. In lxc, fwupd daemon
fails with this error:
Failed to load engine: Failed to load config: cannot process file of type
application/x-zerosize
namespace failures
--------------------------
In LXC the host shows this in dmesg when trying to start the daemon:
[ 3760.599980] audit: type=1400 audit(1550199530.985:19): apparmor="DENIED"
operation="mount" info="failed flags match" error=-13
profile="lxc-container-default-cgns" name="/" pid=13833 comm="(fwupd)"
flags="rw, rslave"
Checking the systemd unit journal this is shown:
● fwupd.service - Firmware update daemon
Loaded: loaded (/lib/systemd/system/fwupd.service; static; vendor preset:
enabled)
Active: failed (Result: exit-code) since Fri 2019-02-15 02:52:33 UTC; 8s ago
Docs: https://fwupd.org/
Process: 3945 ExecStart=/usr/lib/fwupd/fwupd (code=exited,
status=226/NAMESPACE)
Main PID: 3945 (code=exited, status=226/NAMESPACE)
Feb 15 02:52:33 autopkgtest-testing systemd[1]: Starting Firmware update
daemon...
Feb 15 02:52:33 autopkgtest-testing systemd[3945]: fwupd.service: Failed to set
up mount namespacing: Permission denied
Feb 15 02:52:33 autopkgtest-testing systemd[3945]: fwupd.service: Failed at
step NAMESPACE spawning /usr/lib/fwupd/fwupd: Permission denied
Feb 15 02:52:33 autopkgtest-testing systemd[1]: fwupd.service: Main process
exited, code=exited, status=226/NAMESPACE
Feb 15 02:52:33 autopkgtest-testing systemd[1]: fwupd.service: Failed with
result 'exit-code'.
Feb 15 02:52:33 autopkgtest-testing systemd[1]: Failed to start Firmware update
daemon.
Looking around this points at the following apparmor issue potentially.
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/1811248
