Dependabot group update doesn't work on dockerfile

[ying-jeanne]

Is there an existing issue for this?

• I have searched the existing issues

Package ecosystem

Docker

Package manager version

No response

Language version

No response

Manifest location and content before the Dependabot update

The related log is https://github.com/ying-jeanne/mimir/network/updates/716250888

dependabot.yml content

here https://github.com/ying-jeanne/mimir/blob/test_group_update/.github/dependabot.yml

Updated dependency

any dependency in dockerfile, including the ones in the log
updater | +-------------------------------------+
updater | | Dependencies failed to update |
updater | +---------------------+---------------+
updater | | kustomize/kustomize | unknown_error |
updater | | alpine/helm | unknown_error |
updater | | golang | unknown_error |

What you expected to see, versus what you actually saw

dependency update for dockerfile works and one PR raised per dockerfile.

Native package manager behavior

this is not applied

Images of the diff or a link to the PR, issue, or logs

The related log is https://github.com/ying-jeanne/mimir/network/updates/716250888

Smallest manifest that reproduces the issue

you should be able to reproduce it with the same dependabot.yml by fork grafana/mimir repo

[Nishnha]

Thank you for the report!
Adding some context from the logs

updater | ERROR undefined method `segments' for "1.21.0-bullseye":String
updater | 
updater |           major: version.segments[0] || 0,
updater |                         ^^^^^^^^^
updater | ERROR /home/dependabot/dependabot-updater/lib/dependabot/updater/group_update_creation.rb:233:in `semver_segments'
updater | ERROR /home/dependabot/dependabot-updater/lib/dependabot/updater/group_update_creation.rb:221:in `semver_rules_allow_grouping?'

This same error actually shows up in the logs twice:

updater | ERROR undefined method `segments' for "3.12.3":String

[Nishnha]

These dependencies should now be able to update correctly #7984