Problem

The Naginator plugin supports both:

• manual "Retry" of a completed build
• "Rerun build only for failed parts on the matrix"

However, for a matrix project these two features do not work together in the way a user would reasonably expect.

When the automatic Naginator retry runs, failed matrix combinations can be retried selectively.

When the user manually clicks "Retry" on the parent matrix build, however, the new build runs all matrix combinations, including combinations that previously succeeded.

There is currently no way from the manual Retry action to choose which matrix combinations should be rerun.

Example

Consider a matrix job with four combinations:

skymap2  FAILURE
skymap3  SUCCESS
skymap4  FAILURE
skymap5  SUCCESS

The project has "Rerun build only for failed parts on the matrix" enabled.

For automatic retry, the expected behavior is to rerun only:

skymap2
skymap4

But clicking the manual "Retry" action on the parent build creates a new matrix build containing all four combinations:

skymap2
skymap3
skymap4
skymap5

This is especially surprising because the job configuration already says to rerun only failed parts of the matrix.

Proposed behavior

For a MatrixBuild, clicking "Retry" should open a confirmation/selection page rather than immediately scheduling the build.

The page should list the combinations from the original matrix build, for example:

[x] skymap2   FAILURE
[ ] skymap3   SUCCESS
[x] skymap4   FAILURE
[ ] skymap5   SUCCESS

        [Retry selected]

Suggested behavior:

• Show all combinations that existed in the original matrix build.
• Preselect failed combinations.
• Leave successful combinations unselected by default.
• Allow the user to manually select or deselect combinations.
• "Retry selected" should schedule the parent MatrixBuild containing only those selected combinations.
• Preserve the existing immediate Retry behavior for non-matrix jobs.

This would also allow useful manual cases such as retrying one failed combination while deliberately leaving another failed host offline for maintenance, or optionally rerunning an additional successful combination.

Matrix child Retry

There is a related issue with the Retry action being shown on individual MatrixRun children.

Trying to retry an individual matrix child can be rejected by Jenkins because a matrix configuration cannot be independently triggered without its parent.

This is already tracked by JENKINS-61491.

It may therefore make sense to hide the manual Retry action on MatrixRun children and expose the combination-selection UI only on the parent MatrixBuild.

Related issues

• JENKINS-23032 - added support for rerunning only failed parts of a matrix job
• JENKINS-61491 - Retry on a child of a multi-configuration job does not work

The selective automatic matrix retry functionality already exists, so this proposal is primarily about exposing equivalent matrix-awareness in the interactive/manual Retry workflow.

Expected result

Manual Retry on a matrix parent gives the user explicit control over which matrix combinations are scheduled, with failed combinations selected by default.

Actual result

Manual Retry on a matrix parent schedules all combinations, even when only some combinations failed.