Git submodule first triage response

When this happens

Use this when only the visible message is known. Do not stop at the screen message; validate the first observable mismatch before any setting is changed first.

Symptom checklist

• submodule appears repeatedly in the Git UI or logs.
• HEAD, upstream, rebase state, hooks, LFS differs between successful and failed requests.
• The issue appears only after separating local worktree issue from remote rejection.
• It often follows deploys, permission changes, configuration edits, or data refreshes.

Likely causes

• submodule specifically changes the investigation surface for Git: verify the exact failing object, route, user, and timestamp before applying the broader pattern.
• The requested path reaches a server block, ingress, or router that does not own it.
• A rewrite or permalink rule captures the route before the intended handler.
• Static output, submodule content, or uploaded files were not deployed.
• The host header maps to a default virtual host instead of the target site.
• A cache serves an old 404 after the route has been added.
• For the first triage case, the first useful clue is the first observable mismatch before any setting is changed.

First 1-minute checks

1. Write down the first failure time, latest change, affected user, path, and object ID.
2. Compare HEAD, upstream, rebase state, hooks, LFS for success and failure in the same window.
3. Test the hypothesis: routing failure caused by missing route, wrong virtual host, rewrite rule, permalink cache, ingress rule, or missing deployed file.
4. Classify this as first triage: the first observable mismatch before any setting is changed.
5. Capture current values before changing configuration.

First evidence

Treat submodule as a first triage case. First collect evidence for the first observable mismatch before any setting is changed.

Output examples

Normal output

No matching error appears during the affected request window.

Failing output

The same error appears at the exact request time with the affected path, user, or object.

Output-to-action branches

• Only the visible message is known.
  Collect timestamp, route, request ID, user, and the first backend log line before editing configuration.
• The working and failing outputs differ.
  Act on the differing layer first: For submodule, apply the fix only after reproducing the same condition and saving the before/after evidence for this exact code.
• Command output is normal but users still fail.
  Separate browser cache, cookies, permissions, and network location before declaring it fixed.

Do not do this

• Do not change DNS, SSL, cache, and permissions at the same time.
• Do not change multiple layers before identifying the failing layer.
• Do not delete production data, grant broad permissions, or disable security controls as a first response.

Evidence quality

Auto-generated operator draft: includes issue-specific causes, commands, output branches, and unsafe-action warnings. Official-source links and real incident validation are queued for enrichment.

Commands to run first

grep -R "submodule" ./logs

git status --short --branch

git log --oneline --decorate -5

git remote -v

git ls-files -s | head

curl -I https://example.com/missing-path

grep -R "404\|not found\|rewrite\|permalink" ./logs

nginx -T | grep -n "server_name\|rewrite\|location"

date -u && grep -R "ERROR\|WARN\|failed" ./logs | tail -n 50

Fix order

1. Record the full submodule message, failing URL, user, object ID, and latest change.
2. Collect issue-specific evidence for routing failure caused by missing route, wrong virtual host, rewrite rule, permalink cache, ingress rule, or missing deployed file.
3. Compare the failing case with a successful case before editing settings.
4. If this is the first triage branch, Collect timestamp, route, request ID, user, and the first backend log line before editing configuration.
5. Re-check with the same command and URL, then record the normal output.

Actions by cause

• For submodule, apply the fix only after reproducing the same condition and saving the before/after evidence for this exact code.
• Check host and path routing before changing application code.
• Print rewrite, ingress, or server configuration and verify rule order.
• Confirm the built artifact actually contains the expected file or route.
• Purge CDN and application route cache after fixing the origin route.
• Add a regression URL check for the exact failing path.
• For the first triage branch, Collect timestamp, route, request ID, user, and the first backend log line before editing configuration.

Evidence links

• Git documentation official
• GitHub authentication troubleshooting official

Verification metadata

• operator-draft
• official-reference-linked
• 2026-07-23

Update queue

• Review cadence
  weekly-source-review
• Next enrichment
  Add one official-source check and one real output example for Git submodule.

Environment-specific checks

• Shared hosting, proxies, VPNs, or CDN layers can change local worktree issue from remote rejection results.
• Do not trust only the Git UI; compare command output.
• Japanese hosting panels may show completion before DNS or SSL fully propagates.
• Test from both office and external networks.

Prevent it next time

• Store normal examples for HEAD, upstream, rebase state, hooks, LFS.
• Add rebase/merge cleanup, upstream reset, LFS tracking, hook logs to the release checklist.
• Keep recurring errors in the same note format.
• Split alerts by error rate, latency, certificates, disk, and permission changes.

Related notes

• Git merge conflict first triage response
• Git non-fast-forward first triage response
• Git detached HEAD first triage response
• Git permission denied publickey first triage response
• Git large file first triage response
• Git rebase conflict first triage response
• Git line endings first triage response
• Git tag exists first triage response