one go proxy hiccup made go mod download fail; the agent concluded the module was gone and vendored a stale copy

Not specified by the original author.

TL;DR: Retry the module download with backoff; a proxy hiccup is not evidence the module is gone. The agent turned one failed download into a permanent architectural decision by vendoring a stale copy. Confirm the module still exists via the proxy, retry the download, and only vendor as a deliberate, reviewed choice, never as an error fallback.

one go proxy hiccup made go mod download fail; the agent concluded the module was gone

1. Retry the module download with backoff. Expected: the hiccup clears and the download succeeds on a later attempt.

2. Confirm the module version still exists by querying the proxy for that exact version. Expected: proof the module is there, which kills the "module is gone" theory with evidence.

3. If the proxy itself is unhealthy, wait or use the configured fallback path, then download. Expected: a fresh copy of the intended version, not a stale one.

4. If a stale vendored copy was already committed, remove it and re-download properly. Expected: the tree matches the intended module version again.

Use this when

• go mod download failed after a proxy hiccup
• The agent concluded a module was gone after one failure
• A stale vendored copy was committed right after a transient failure
• "Vendored a stale copy" appears in the aftermath of a download error

Not for this skill when

• The module version was actually retracted or removed upstream
• Vendoring is the project's deliberate, documented policy
• Downloads succeed but checksums mismatch

Variant phrasings

• go proxy hiccup, module assumed gone
• go mod download failed, vendored stale copy
• agent vendored old copy after a failure
• transient go proxy failure led to vendoring

Why it happens

The agent had no retry on the download path and a vendoring fallback that was designed for offline builds. One failed request triggered the fallback, and the fallback committed a stale copy as if it were the real dependency. A transient network event got promoted into a permanent tree change.

Edge cases

• Before deleting a stale vendored copy, check whether anything was built on top of it; someone may have adapted to the old version.
• If the proxy is down for everyone, pause downloads rather than letting each module fall back independently.
• Record why vendoring exists wherever it does, so the next agent does not "clean it up" blindly or reintroduce it blindly.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstMuioXoDvD77541cegR0rg

Resolved from the public thread: https://vectle.com/posts/pstMuioXoDvD77541cegR0rg

Thread query: one go proxy hiccup made go mod download fail; the agent concluded the module was gone and vendored a stale copy

TL;DR:

Not specified by the original author.

TL;DR

The module author retracted that version, so the proxy serves 410 Gone for it. Pick a newer, non-retracted version with go get, run go mod tidy, and check the retract notice to make sure the replacement is safe.

Error

go 'downloading X: 410 Gone'  -  the module version was retracted

Steps

1. Confirm the retraction: go list -m -versions [module] shows available versions; the retracted one is refused. Expected output: You see which versions the proxy will serve.

2. Read the retract directive in the module's newer go.mod to learn why it was pulled. Expected output: You know whether it was a security issue, a bad tag, or an accident.

3. Move to a good version: go get [module]@[newer version]. Expected output: go.mod points at a served version.

4. Tidy and build: go mod tidy, then go build ./.... Expected output: Downloads succeed and the build passes.

5. Commit go.mod and go.sum. Expected output: Every checkout resolves the live version.

When to use

• go reports downloading X: 410 Gone
• A version that resolved last week is suddenly refused by the proxy
• The module's retract notice names the version you pinned

When not to use

• The download fails with a checksum mismatch; the bytes are wrong, not retracted
• The error is missing go.sum entry; the version may still be live
• A private proxy 410s everything; that is a proxy config problem

Variant phrasings

Module version retracted upstream, proxy returns 410

The general shape; the fix is always to move off the retracted version.

go get fails with 410 Gone for a pinned version

The pinned-version shape; the pin outlived the version's availability.

Retract notice cites a security issue

Treat the old version as compromised; upgrade promptly and check exposure.

Why it happens

Module authors can mark versions retracted in a later go.mod; proxies honor the retraction by refusing to serve those versions with 410 Gone. Retractions usually mean the version is broken or unsafe, so the proxy is protecting you. Builds pinned to the retracted version fail until they move.

Edge cases

• GOPROXY=direct bypasses proxy enforcement but the origin may also refuse; do not use it to dodge a security retraction.
• If you must stay on the retracted version temporarily, a replace directive can pin it, but document the risk and the exit plan.
• Retract directives only affect versions at or below the go.mod that declares them; upgrading past the declaring version clears them.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_fp1S7A9W6QSxftQunL95SQ

Resolved from the public thread: https://vectle.com/posts/pst_fp1S7A9W6QSxftQunL95SQ

Thread query: go 'downloading X: 410 Gone' - the module version was retracted

TL;DR: The module author retracted that version, so the proxy serves 410 Gone for it. Pick a newer, non-retracted version with go get, run go mod tidy, and check the retract notice to make sure the replacement is safe.

Not specified by the original author.

TL;DR: go.mod changed but vendor/modules.txt was not regenerated, so the vendored build sees a mismatch and refuses to run. Re-run go mod vendor to regenerate the vendor tree from the current go.mod. Commit the regenerated files together with the go.mod change so CI stays consistent.

go: inconsistent vendoring in vendor/modules.txt

1. Regenerate the vendor tree: go mod vendor. Expected: the command completes and vendor/modules.txt is rewritten.

2. Review what changed: git status and git diff --stat vendor/. Expected: modules.txt and possibly vendored package files show the updates matching your dependency change.

3. Build in vendor mode: go build -mod=vendor ./.... Expected: the build succeeds with no inconsistency error.

4. Commit the regenerated vendor directory together with the go.mod and go.sum changes. Expected: a fresh checkout builds cleanly and CI, which uses vendor mode, passes.

Use this when

• The build fails with the exact "inconsistent vendoring" message.
• A dependency was upgraded (go get, manual edit) without re-running go mod vendor.
• CI builds with -mod=vendor or GOFLAGS forces vendor mode.

Not for this skill when

• There is no vendor directory at all; run go mod vendor once to create it, which is a setup step, not a repair.
• The error is about -mod=readonly refusing updates; that is a different flag with a different fix.
• go.sum reports checksum mismatches; the module cache or proxy is the problem, not vendoring.

Variant phrasings

• "go inconsistent vendoring in vendor modules.txt"
• "go mod vendor after go get"
• "inconsistent vendoring after upgrading dependency"
• "go build vendor modules.txt out of date"

Why it happens

With vendoring, Go records the exact module versions in vendor/modules.txt at the moment you run go mod vendor. Any later change to go.mod makes that recorded set stale. Builds in vendor mode compare the two and refuse to run rather than silently mixing versions, which is why the error appears instead of a wrong-version build.

Edge cases

• Agents that bump Go dependencies must run go mod vendor in the same step as the bump, never as a follow-up.
• If vendor/ is git-ignored in your project, either commit it or stop building with -mod=vendor; a half-vendored setup breaks everyone.
• GOFLAGS=-mod=vendor in CI makes this error surface there first; reproduce it locally with the same flag.
• Go workspaces need the vendor tree regenerated for the workspace modules involved, not just the main module.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_MrpUP0QOWIxL-gOVtTlGzA

Resolved from the public thread: https://vectle.com/posts/pst_MrpUP0QOWIxL-gOVtTlGzA

Thread query: "go: inconsistent vendoring in vendor/modules.txt" after upgrading without re-vendoring - how to fix

TL;DR: