Disable TRAP caching when overlay is enabled by henrymercer · Pull Request #3569 · github/codeql-action · GitHub

Overlay supersedes TRAP caching, so when overlay is enabled, we should avoid spending time downloading and generating TRAP caches, and free up Actions cache space by not storing TRAP caches.

Risk assessment

For internal use only. Please select the risk level of this change:

Low risk: Changes are fully under feature flags, or have been fully tested and validated in pre-production environments and are highly observable, or are documentation or test only.

Which use cases does this change impact?

Workflow types:

Advanced setup - Impacts users who have custom CodeQL workflows.
Managed - Impacts users with dynamic workflows (Default Setup, Code Quality, ...).

Products:

Code Scanning - The changes impact analyses when analysis-kinds: code-scanning.

Environments:

Dotcom - Impacts CodeQL workflows on github.com and/or GitHub Enterprise Cloud with Data Residency.

How did/will you validate this change?

Unit tests - I am depending on unit test coverage (i.e. tests in .test.ts files).

If something goes wrong after this change is released, what are the mitigation and rollback strategies?

Feature flags - All new or changed code paths can be fully disabled with corresponding feature flags.

How will you know if something goes wrong after this change is released?

Telemetry - I rely on existing telemetry or have made changes to the telemetry.
- Dashboards - I will watch relevant dashboards for issues after the release. Consider whether this requires this change to be released at a particular time rather than as part of a regular release.

Are there any special considerations for merging or releasing this change?

No special considerations - This change can be merged at any time.

Merge / deployment checklist

Confirm this change is backwards compatible with existing workflows.
Consider adding a changelog entry for this change.
Confirm the readme and docs have been updated if necessary.

Pull request overview

This PR refactors TRAP caching setup so it’s decided inside config initialization, and adds a feature-flagged behavior to disable TRAP caching when overlay analysis (improved incremental analysis) is enabled.

Changes:

Move TRAP caching enablement logic (incl. C++ env var handling) into src/config-utils.ts, with new isTrapCachingEnabled and associated tests.
Remove legacy CodeQL CLI version gating for database cleanup now that the Action enforces a newer minimum CLI version.
Update tests/utilities and changelog to reflect the new behavior.

Reviewed changes

Copilot reviewed 15 out of 19 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/testing-utils.ts	Adds RUNNER_NAME to default Actions env vars used by tests.
src/init-action.ts	Removes inline TRAP caching + Python warning suppression logic now handled elsewhere.
src/feature-flags.ts	Adds OverlayAnalysisDisableTrapCaching feature flag and reorganizes overlay-related flags.
src/config-utils.ts	Implements isTrapCachingEnabled, downloads TRAP caches conditionally, and sets C++ TRAP caching env var when enabled.
src/config-utils.test.ts	Adds unit tests for isTrapCachingEnabled and initializes Actions env vars in more tests.
src/codeql.ts	Always uses --cache-cleanup for database cleanup now that minimum CLI supports it.
lib/upload-lib.js	Generated JS output update (not reviewed).
lib/start-proxy-action.js	Generated JS output update (not reviewed).
lib/setup-codeql-action.js	Generated JS output update (not reviewed).
lib/resolve-environment-action.js	Generated JS output update (not reviewed).
CHANGELOG.md	Documents the experimental rollout to disable TRAP caching under overlay analysis.

The overlay-related entries in featureConfig are no longer kept in alphabetical order: OverlayAnalysisSkipResourceChecks comes after OverlayAnalysisStatusCheck/Save. Please reorder these keys to match the established convention in this file (keeps diffs smaller and makes it easier to scan for flags).

setCppTrapCachingEnvironmentVariables only ever sets CODEQL_EXTRACTOR_CPP_TRAP_CACHING to true. Previously the action explicitly set this env var to false when TRAP caching was not enabled. Leaving it unset makes behavior dependent on the extractor default and may fail to actually disable C++ TRAP caching when isTrapCachingEnabled returns false (e.g., when overlay analysis is on). Consider adding an explicit disable path when TRAP caching is disabled (while still respecting a user-supplied env var).

Suggested change

      
                } else {
          
                  logger.info("Enabling CodeQL C++ TRAP caching support.");
          
                  core.exportVariable(envVar, "true");
          
                  return;
          
                }
          
                if (config.trapCachingEnabled) {
          
                  logger.info("Enabling CodeQL C++ TRAP caching support.");
          
                  core.exportVariable(envVar, "true");
          
                } else {
          
                  logger.info("Disabling CodeQL C++ TRAP caching support.");
          
                  core.exportVariable(envVar, "false");

I assume Henry has checked the default, but it probably wouldn't hurt to still explicitly set it to false.

Looks good, thanks for putting the changed behaviour behind a FF as well!

Copilot's comment about the CPP env var potentially not being set at all is true I think. I assume the default behaviour if for it to be false, but it may not hurt to just set it to false anyway.

I probably would have preferred for the drive-by changes in this PR to be in their own PRs. They made it a bit harder than necessary to review this change, and it might be tricky to track them down later.

I assume Henry has checked the default, but it probably wouldn't hurt to still explicitly set it to false.

# Conflicts: # lib/start-proxy-action.js

LGTM!

henrymercer added 10 commits March 11, 2026 18:44

Add FF for disabling TRAP caching when overlay enabled

b0f8772

Enablement: Move TRAP caching check after overlay

b04e63f

Disable TRAP caching when conditions met

70d5ccc

Clean up: Remove unneeded CodeQL version guard

d05b50b

Drive-by cleanup: Always use --cache-cleanup

d74701c

Remove dead Python library extraction code

19544bb

Drive-by comment fixes

556dd79

Add unit tests for isTrapCachingEnabled

a91b7a3

Add changelog note

b1f1e7b

Stub RUNNER_NAME in unit tests

926e6df

henrymercer requested a review from a team as a code owner March 11, 2026 20:19

Copilot AI review requested due to automatic review settings March 11, 2026 20:19

github-actions Bot added the size/L May be hard to review label Mar 11, 2026

Copilot started reviewing on behalf of henrymercer March 11, 2026 20:20 View session

Copilot AI reviewed Mar 11, 2026

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redsun82 previously approved these changes Mar 12, 2026

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mbg previously approved these changes Mar 12, 2026

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henrymercer added 2 commits March 18, 2026 16:35

Merge branch 'main' into henrymercer/overlay-no-trap-caching

60a0dce

# Conflicts: # lib/start-proxy-action.js

Explicitly set C/C++ trap caching env var to false

582d08c

henrymercer dismissed stale reviews from mbg and redsun82 via 582d08c March 18, 2026 17:10

Fix changelog automerge

5b63048

henrymercer requested a review from redsun82 March 18, 2026 17:11

redsun82 approved these changes Mar 19, 2026

View reviewed changes

henrymercer added this pull request to the merge queue Mar 19, 2026

Merged via the queue into main with commit 07d509f Mar 19, 2026
225 checks passed

henrymercer deleted the henrymercer/overlay-no-trap-caching branch March 19, 2026 10:32

This was referenced Mar 20, 2026

Merge main into releases/v4 #3588

Merged

Merge releases/v4 into releases/v3 #3590

Merged

github-actions Bot mentioned this pull request May 18, 2026

chore(ci)(deps): bump github/codeql-action from 3.35.4 to 4.35.5 ag-ui-protocol/ag-ui#1711

Closed

+                  defaultValue: false,
+                  envVar: "CODEQL_ACTION_OVERLAY_ANALYSIS_STATUS_SAVE",
+                  minimumVersion: undefined,
                 },
                 [Feature.OverlayAnalysisSkipResourceChecks]: {

Disable TRAP caching when overlay is enabled by henrymercer · Pull Request #3569 · github/codeql-action · GitHub

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Disable TRAP caching when overlay is enabled - #3569

Disable TRAP caching when overlay is enabled#3569
henrymercer merged 13 commits into
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henrymercer commented Mar 11, 2026

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Disable TRAP caching when overlay is enabled by henrymercer · Pull Request #3569 · github/codeql-action · GitHub

Uh oh!

Disable TRAP caching when overlay is enabled - #3569

Disable TRAP caching when overlay is enabled#3569henrymercer merged 13 commits intomaingithub/codeql-action:mainfrom henrymercer/overlay-no-trap-cachinggithub/codeql-action:henrymercer/overlay-no-trap-cachingCopy head branch name to clipboard

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henrymercer commented Mar 11, 2026

Risk assessment

Which use cases does this change impact?

How did/will you validate this change?

If something goes wrong after this change is released, what are the mitigation and rollback strategies?

How will you know if something goes wrong after this change is released?

Are there any special considerations for merging or releasing this change?

Merge / deployment checklist

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Disable TRAP caching when overlay is enabled#3569
henrymercer merged 13 commits into
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henrymercer/overlay-no-trap-caching