[3.1][3.1+snap7] /proc/ not mounted

[Erich Eickmeyer]

It appears as though the chroot cannot or does not mount /proc/ which is causing this error:

$ sudo ubuntu-image -v classic -w workdir/ -O output/ ubuntu-images/ubuntu-pi-arm64.yaml
[0] make_temporary_directories
[1] determine_output_directory
[2] build_gadget_tree
[3] prepare_gadget_tree
[4] load_gadget_yaml
[5] verify_artifact_names
[6] germinate
[7] create_chroot
[8] install_packages
[9] prepare_image
Fetching firefox (3627)
Fetching gnome-42-2204 (143)
Fetching gtk-common-themes (1535)
Fetching snap-store (1047)
Fetching snapd-desktop-integration (85)
Fetching core22 (1035)
Fetching bare (5)
Fetching snapd (20674)
[10] preseed_image
[11] clean_rootfs
[12] customize_sources_list
[13] customize_fstab
[14] perform_manual_customization
Error: Error running script "/usr/sbin/chroot workdir/chroot /usr/sbin/oem-config-prepare". Error is exit status 1. Full output below:
⚠️ /proc/ is not mounted. This is not a supported mode of operation. Please fix
your invocation environment to mount /proc/ and /sys/ properly. Proceeding anyway.
Your mileage may vary.
Created symlink /etc/systemd/system/oem-config.target.wants/oem-config.service → /lib/systemd/system/oem-config.service.
⚠️ /proc/ is not mounted. This is not a supported mode of operation. Please fix
your invocation environment to mount /proc/ and /sys/ properly. Proceeding anyway.
Your mileage may vary.
The unit files have no installation config (WantedBy=, RequiredBy=, Also=,
Alias= settings in the [Install] section, and DefaultInstance= for template
units). This means they are not meant to be enabled or disabled using systemctl.

Possible reasons for having this kind of units are:
• A unit may be statically enabled by being symlinked from another unit's
  .wants/ or .requires/ directory.
• A unit's purpose may be to act as a helper for some other unit which has
  a requirement dependency on it.
• A unit may be started when needed via activation (socket, path, timer,
  D-Bus, udev, scripted systemctl call, ...).
• In case of template units, the unit is meant to be enabled with some
  instance name specified.
⚠️ /proc/ is not mounted. This is not a supported mode of operation. Please fix
your invocation environment to mount /proc/ and /sys/ properly. Proceeding anyway.
Your mileage may vary.
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/oem-config.target.
sudo: unknown user oem
sudo: error initializing audit plugin sudoers_audit

[Simon Quigley (tsimonq2)]

I can reproduce this after building the snap based on the 3.0 tag upstream, in addition to the latest stable channel.

[Paul Mars (upils)]

It looks like a duplicate of LP: #2035216. Probably worth investigating but the root cause is not new.

I also faced this bug once and Steve provided some input as to how solve this in [0]

[0] https://bugs.launchpad.net/ubuntu-image/+bug/2045336/comments/3

[Paul Mars (upils)]

I think this will be solved when [0] is merged because the execution of oem-config-prepare will disappear.

[0] https://code.launchpad.net/~waveform/ubuntu-images/+git/ubuntu-images/+merge/456465

[Erich Eickmeyer (eeickmeyer)]

> I think this will be solved when [0] is merged because the execution of oem-config-prepare will disappear.

Yeah, and I'll have to figure out how to mirror that with Edubuntu, so we'll see how that goes.

[Erich Eickmeyer (eeickmeyer)]

Ok, so good news is unsetting $DISPLAY before execution did resolve this. I'll mark this bug as duplicate of LP: #2035216 and remark about Steve's comment with that as the solution for the issue when running on a desktop install, along with an idea on how to fix long-term since merely waiting for oem-config-prepare to disappear isn't exactly fixing the problem correctly.