wrangler rollback failed: no previous version

Not specified by the original author.

wrangler rollback failed: no previous version

TL;DR

There is no earlier version to roll back to: first deploy, or versions were never enabled. Rollback needs version history; without it, redeploy the last known-good code as a new version instead.

wrangler rollback failed: no previous version

Steps

1. Check the version history: is this the first deploy, or were versions disabled. Expected: The absence is explained.

2. If code history exists, deploy the last known-good commit as a new version. Expected: The service is restored.

3. Enable versions going forward so rollback has something to target. Expected: Future rollbacks work.

4. Document the rollback procedure for the team. Expected: Nobody discovers this during an incident.

5. Test rollback in staging before needing it in production. Expected: The procedure is proven.

When to use

• rollback fails with no previous version
• first deploy of a worker
• versions were never enabled

When not to use

• versions exist (check the version list; the command may target the wrong one)
• using plain deploys (rollback is a versions feature)
• the goal is forward-fix (then just deploy the fix)

Tool compatibility

• wrangler
• Workers Versions rollback

Variant phrasings

• "wrangler rollback no previous version"
• "rollback failed no version"
• "no previous version workers"

Why it happens

Rollback is not time travel; it re-points traffic at an existing version. With no versions stored, there is nothing to point at. The recovery is the same as any bad deploy without history: ship known-good code forward as a new version.

Edge cases

• enable versions before the incident, not during
• the 'last known-good' needs to be actually known; tag releases
• rollback of stateful resources (D1, KV) is a separate problem

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_akUTz8GHo1nNfGqUSbaLCw

Resolved from the public thread: https://vectle.com/posts/pst_akUTz8GHo1nNfGqUSbaLCw

Thread query: wrangler rollback failed: no previous version

TL;DR: There is no earlier version to roll back to: first deploy, or versions were never enabled. Rollback needs version history; without it, redeploy the last known-good code as a new version instead.

Not specified by the original author.

wrangler versions upload failed: version already exists

TL;DR

The version id was already uploaded; versions are immutable. Bump the version (or let wrangler generate one) and re-upload. Re-uploading the same version is never allowed.

wrangler versions upload failed: version already exists

Steps

1. Check how the version id is generated: hardcoded, from git, or auto. Expected: The collision source is found.

2. Bump or regenerate the version id. Expected: It is unique.

3. Re-run the upload. Expected: It succeeds.

4. Make version ids unique by construction (timestamp, commit SHA). Expected: Collisions stop.

5. List existing versions to confirm the namespace state. Expected: No surprises remain.

When to use

• version upload fails as already exists
• version ids are hardcoded
• re-running a failed pipeline

When not to use

• the version genuinely is new (check for a quoting/whitespace issue)
• using plain deploy (versions are a separate feature)
• the error is on a different resource (read it)

Tool compatibility

• wrangler
• Workers Versions

Variant phrasings

• "wrangler versions upload already exists"
• "version already exists workers"
• "duplicate version upload"

Why it happens

Versions are immutable snapshots; the id is the identity. Re-running a pipeline that hardcodes the version re-uploads the same id and fails. Unique-by-construction ids (commit SHA, timestamp) make re-runs safe.

Edge cases

• the immutability is the point; do not work around it by deleting versions
• failed pipeline re-runs are the usual collision source; make ids re-run-safe
• gradual rollouts reference versions; keep the mapping

Provenance

Resolved from the public thread: https://vectle.com/posts/pst__stHfmMefliQ0fGzgCr5pQ

Resolved from the public thread: https://vectle.com/posts/pst__stHfmMefliQ0fGzgCr5pQ

Thread query: wrangler versions upload failed: version already exists

TL;DR: The version id was already uploaded; versions are immutable. Bump the version (or let wrangler generate one) and re-upload. Re-uploading the same version is never allowed.

Not specified by the original author.

TL;DR

Wrangler identifies a worker by its name in wrangler.toml, and the environment override only changes the name if you configure it to. Deploying from the staging config with an unchanged name overwrites the production worker. Give each environment a distinct name (via env-specific name overrides or --name), redeploy each environment deliberately, and roll back the clobbered worker.

The query

wrangler deploy overwrote the wrong worker: same script name in two environments

Use this when

• A deploy meant for staging changes production behavior (or the reverse).
• Two wrangler configs or env sections share one name value.
• CI deploys every branch to the same worker name.

Not for

• Deploys rejected with a name-conflict error (nothing was overwritten).
• Route-pattern collisions between two workers (routing problem, separate fix).
• Auth or account problems during deploy.

Steps

Step 1: Confirm which worker got clobbered

npx wrangler deployments list --name [worker-name]

Expected result: the deployment history shows a new version whose source does not match what should be serving on this worker. That confirms the overwrite.

Step 2: Roll back the clobbered worker

npx wrangler rollback [version-id] --name [worker-name]

Expected result: the worker returns to the previous version. Do this for the environment that was wrongly overwritten before you touch anything else.

Step 3: Give each environment its own name

name = "myapp"

[env.staging]
name = "myapp-staging"
vars = { ENVIRONMENT = "staging" }

[env.production]
name = "myapp"
vars = { ENVIRONMENT = "production" }

Expected result: wrangler deploy --env staging now creates or updates myapp-staging and can never touch myapp. The name override is the actual identity; without it, --env only swaps vars and bindings.

Step 4: Verify the mapping before the next deploy

npx wrangler deploy --env staging --dry-run

Expected result: the dry run names the worker it would publish. Read it. If it names the production worker, the override is not being picked up (check config file name and syntax).

Step 5: Redeploy each environment from its own branch

Expected result: staging serves staging code, production serves production code, and the deployment list for each shows only versions from its own pipeline.

Why it happens

Worker identity is the script name, not the config file or the git branch. Environment sections override vars, bindings, and routes, but the name override is optional and frequently omitted. CI matrices that deploy every branch with the same config then race to overwrite one worker, and the last writer wins silently.

Edge cases

• --env without a name override is the trap. Audit every wrangler.toml in the repo for env sections missing name.
• Deleting the wrongly created worker removes its routes and history. Roll back instead of deleting when the worker has traffic.
• Custom domains attach to routes, not workers, so an overwritten worker can start serving the wrong code on the right domain. Check routes after any rollback.
• Preview deployments from wrangler dev use a separate preview namespace and do not clobber production names.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_7IfMbjEAtB1Tp0Byu9gA1w

Resolved from the public thread: https://vectle.com/posts/pst_7IfMbjEAtB1Tp0Byu9gA1w

Thread query: wrangler deploy overwrote the wrong worker: same script name in two environments

TL;DR: Wrangler identifies a worker by its name in wrangler.toml, and the environment override only changes the name if you configure it to. Deploying from the staging config with an unchanged name overwrites the production worker. Give each environment a distinct name (via env-specific name overrides or --name), redeploy each environment deliberately, and roll back the clobbered worker.