What causes "A deleted cross-listing failed: #{e}" in instructure/canvas-lms?

Inspect the wrapped message after 'A deleted cross-listing failed:' for the root cause

instructure/canvas-lms · error · ImportError

A deleted cross-listing failed: #

Error message

A deleted cross-listing failed: #{e}

What it means

When applying a 'deleted' cross-listing (uncross-listing), section.uncrosslist is wrapped in a rescue that re-raises ImportError with "A deleted cross-listing failed: #{e}". Any failure moving the section back to its original (nonxlist) course is converted into this ImportError with the underlying message appended.

Solutions

Inspect the wrapped message after 'A deleted cross-listing failed:' for the root cause
Verify the section's nonxlist_course_id / original course still exists and is not deleted
Re-run the SIS import after repairing course/section data
Check inline job logs (run_jobs_immediately: true) for the failing step

Defensive patterns

Strategy: try-catch

Validate before calling

section = root_account.course_sections.find_by(sis_source_id: section_id)
if section && section.nonxlist_course_id && !root_account.all_courses.exists?(section.nonxlist_course_id)
  raise "Original course #{section.nonxlist_course_id} missing; cannot uncrosslist"
end

Try / catch

begin
  xlist.add_crosslist(xlist_course_id, section_id, 'deleted')
rescue SIS::ImportError => e
  cause = e.message.sub(/\AA deleted cross-listing failed: /, '')
  Rails.logger.error("Uncrosslist failed: #{cause}")
end

Prevention

Verify nonxlist_course_id points to an existing course before uncrosslisting
Restore soft-deleted original courses before processing deletes
Avoid concurrent mutation of sections during import
Watch inline job logs when run_jobs_immediately: true

When it happens

Trigger: add_crosslist with status 'deleted' where the section currently sits in the xlist course (section.course_id == @course.id or @course is nil) and uncrosslist raises — DB errors, invalid original course state, or callback/job failures with run_jobs_immediately: true.

Common situations: The section's nonxlist_course_id points at a deleted or missing course; concurrent edits to the section during SIS import; inline job failures while restoring enrollments during uncrosslist.

Related errors

AI-assisted analysis of instructure/canvas-lms@1c9f0bb801 (2026-09-15). Data as JSON: /api/errors/10ebf4141e5875e9. Report an issue: GitHub.

Appendix: source

Thrown at lib/sis/xlist_importer.rb:117

            begin
              @course_ids_to_update_associations.merge [@course.id, section.course_id, section.nonxlist_course_id].compact
              section.crosslist_to_course(@course, run_jobs_immediately: true)
            rescue => e
              raise ImportError, "An active cross-listing failed: #{e}"
            end

          when /\Adeleted\z/i
            if @course && section.course_id != @course.id
              @success_count += 1
              return
            end

            begin
              @course_ids_to_update_associations.merge [section.course_id, section.nonxlist_course_id]
              section.uncrosslist(run_jobs_immediately: true)
            rescue => e
              raise ImportError, "A deleted cross-listing failed: #{e}"
            end

          else
            raise ImportError, "Improper status #{status} for a cross-listing"
          end

          @success_count += 1
        end
      end
    end
  end
end

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