[Bug 2155145] Re: python3-magnum-ui invalid scss variable fails config step

Wed Sep 9 20:17:08 UTC 2026

Hello Guillaume, or anyone else affected,

Accepted magnum-ui into resolute-proposed. The package will build now
and be available at https://launchpad.net/ubuntu/+source/magnum-
ui/18.0.0-0ubuntu1.1 in a few hours, and then in the -proposed
repository.

Please help us by testing this new package.  See
https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
to enable and use -proposed.  Your feedback will aid us getting this
update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug,
mentioning the version of the package you tested, what testing has been
performed on the package and change the tag from verification-needed-
resolute to verification-done-resolute. If it does not fix the bug for
you, please add a comment stating that, and change the tag to
verification-failed-resolute. In either case, without details of your
testing we will not be able to proceed.

Further information regarding the verification process can be found at
https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
advance for helping!

N.B. The updated package will be released to -updates after the bug(s)
fixed by this package have been verified and the package has been in
-proposed for a minimum of 7 days.

** Changed in: magnum-ui (Ubuntu Resolute)
       Status: New => Fix Committed

** Tags added: verification-needed-resolute

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https://bugs.launchpad.net/bugs/2155145

Title:
  python3-magnum-ui invalid scss variable fails config step

Status in Ubuntu Cloud Archive gazpacho series:
  New
Status in OpenStack Snap:
  Triaged
Status in OpenStack Snap 2026.1 series:
  Triaged
Status in magnum-ui package in Ubuntu:
  Fix Released
Status in magnum-ui source package in Resolute:
  Fix Committed
Status in magnum-ui source package in Stonking:
  Fix Released

Bug description:
  [ Impact ]

   * On Resolute, installing `python3-magnum-ui` with `openstack-dashboard` can
     leave both packages unconfigured. During Horizon static-asset compression,
     Magnum UI SCSS uses `$gray-lighter` before the active theme variables are
     imported.

   * This makes the dashboard post-installation step fail and prevents Magnum UI
     from being configured.

   * The update imports the active Horizon theme variables before the Magnum UI
     cluster styles, with the required SCSS syntax.

  [ Test Plan ]

   * Use a disposable fully updated Resolute VM or container. Before enabling
     `resolute-proposed`, install the released packages:

         sudo apt update
         sudo apt install openstack-dashboard python3-magnum-ui

     Confirm the static-asset step fails with an undefined `$gray-lighter`
     variable and leaves the affected packages unconfigured.

   * Enable `resolute-proposed`, update APT metadata, and install the candidate
     `python3-magnum-ui` version. Confirm that APT selected the proposed build.

   * Confirm the installed SCSS imports theme variables before cluster
  styles:

         scss_file=$(dpkg -L python3-magnum-ui | grep '/dashboard/container-infra/container-infra.scss$')
         sed -n '1,2p' "$scss_file"

     The file must first import the active theme variables and then
     `clusters/clusters`.

   * Complete pending configuration and rerun the dashboard
  configuration:

         sudo dpkg --configure -a
         sudo env DEBIAN_FRONTEND=noninteractive dpkg-reconfigure openstack-dashboard
         dpkg-query -W -f='${Package}\t${Version}\t${Status}\n' openstack-dashboard python3-magnum-ui

     Both packages must report `install ok installed`, with no SCSS or undefined
     variable error.

   * On a connected OpenStack deployment, open **Project > Container Infra >
     Clusters** and confirm the page and its styling load correctly.

  [ Where problems could occur ]

   * An incorrect import path, order, or SCSS syntax would again make Horizon's
     static-asset compression fail, potentially leaving `openstack-dashboard`
     unconfigured.

   * Importing theme variables can change Magnum UI styling. Check Container
     Infrastructure panels with the deployment's active theme for broken colours,
     icons, or controls.

   * Both carried changes are required. If either is absent, the package
     configuration failure can return.

  [ Other Info ]

   * LP: #2155145 records the SCSS failure during dashboard package
     configuration.

  `python3-magnum-ui` 18.0.0-0ubuntu1 installs Horizon SCSS static
  assets that reference the undefined variable `$gray-lighter`.

  This breaks `openstack-dashboard` package configuration when
  `openstack-dashboard` and `python3-magnum-ui` are installed together,
  because Horizon’s postinst runs static asset collection and
  compression after the Magnum UI assets are staged.

  ## Affected Packages

  * Source package: `magnum-ui`
  * Binary package: `python3-magnum-ui`
  * Version: `18.0.0-0ubuntu1`
  * Ubuntu series observed: `resolute`
  * Related package: `openstack-dashboard` `4:25.7.1-0ubuntu1`

  ## Steps to Reproduce

  1. In a clean resolute environment, install both packages in one
  transaction:

     `apt install openstack-dashboard python3-magnum-ui`

  2. Observe `openstack-dashboard` postinst running static asset
  collection and compression after both packages are staged.

  ## Error Observed

  `openstack-dashboard` fails to configure during static asset
  compression:

  ```text
  Collecting and compressing static assets...
  CommandError: An error occurred during rendering _stylesheets.html: Error: Undefined variable: "$gray-lighter".
          on line 9:15 of ../../../var/lib/openstack-dashboard/static/dashboard/container-infra/clusters/clusters.scss
          from line 1:9 of ../../../var/lib/openstack-dashboard/static/dashboard/container-infra/container-infra.scss
  >>         fill: $gray-lighter;

     --------------^
  dpkg: error processing package openstack-dashboard (--configure):
   old openstack-dashboard package postinst maintainer script subprocess failed with exit status 1
  ```

  `python3-magnum-ui` is then left unconfigured because its dependency
  on `openstack-dashboard` cannot be satisfied:

  ```text
  dpkg: dependency problems prevent configuration of python3-magnum-ui:
   python3-magnum-ui depends on openstack-dashboard (>= 4:22.2.0+git2022071815.f3767aba9-0ubuntu2~); however:
    Package openstack-dashboard is not configured yet.

  dpkg: error processing package python3-magnum-ui (--configure):
   dependency problems - leaving unconfigured
  ```

  ## Expected Result

  Installing `openstack-dashboard` and `python3-magnum-ui` in the same
  apt transaction should complete successfully.

  The Magnum UI static assets should either avoid references to
  undefined Horizon SCSS variables, import the required variable
  definitions correctly, or be patched to use variables available in the
  packaged Horizon theme stack.

  ## Actual Result

  `openstack-dashboard` fails during postinst static asset compression
  because Magnum UI’s SCSS references `$gray-lighter`, which is not
  defined in the active compression context.

  This leaves both `openstack-dashboard` and `python3-magnum-ui`
  unconfigured.

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