🐛 BUG: nonactionable error about migration

[IgorMinar]

What version of Wrangler are you using?

0.0.0-52ea60f

What operating system are you using?

mac

Describe the Bug

I tried to publish my worker with a DO and I got this error that puzzles me... I have no idea what to do about this:

$ wrangler publish
 ⛅️ wrangler 0.0.0-52ea60f 
---------------------------

✘ [ERROR] Received a bad response from the API

  Migration tag precondition failed; current tag is v1 [code: 10079]

wrangler.toml

name = "request-counter"
main = "src/index.ts"
compatibility_date = "2022-03-25"

[[durable_objects.bindings]]
name = "doRequestCounter"
class_name = "DurableRequestCounter"

[[migrations]]
tag = "v1"
new_classes = ["DurableRequestCounter"]

Could we improve the error message to be actionable?

[IgorMinar]

Oddly.. if I try multiple times, I do get the publish to exit without an error:

$ wrangler publish
 ⛅️ wrangler 0.0.0-52ea60f 
---------------------------

✘ [ERROR] Received a bad response from the API

  Migration tag precondition failed; current tag is v1 [code: 10079]
  
  If you think this is a bug, please open an issue at:
  https://github.com/cloudflare/wrangler2/issues/new


$ wrangler publish
 ⛅️ wrangler 0.0.0-52ea60f 
---------------------------

✘ [ERROR] Received a bad response from the API

  Migration tag precondition failed; current tag is v1 [code: 10079]
  
  If you think this is a bug, please open an issue at:
  https://github.com/cloudflare/wrangler2/issues/new


$ wrangler publish
 ⛅️ wrangler 0.0.0-52ea60f 
---------------------------
Uploaded request-counter (4.09 sec)
Published request-counter (4.51 sec)
  request-counter.swoosh.workers.dev
  * * * * *

[threepointone]

That error is straight from the api, but even I'm not sure what it's indicating; your wrangler.toml looks fine to me

[petebacondarwin]

Had you previously pushed a DO with a different migration for this Worker? Perhaps a different class name?
Can you look in the dashboard to see if there is a DO defined for this Worker?

[petebacondarwin]

In the config service code base we have:

	// old tag provided but different

	if existing != nil && actorMigrations != nil && actorMigrations.OldTag != existing.MigrationTag {
		return "", errors.WithStack(api.ActorTagPreconditionError(existing.MigrationTag))
	}

which is what is causing this error.

So I believe that you must have already used this tag in an other migration, which you have changed?

[threepointone]

I think i might have found some bugs with the way we do migrations, I'll work on it today and add some test coverage.

[IgorMinar]

I'm a bit puzzled about what went wrong here. I've never used any migration except for the v1 "new_classes" migration, which is required for me to deploy the DO.

Initially I deployed the DO successfully (after being asked to add this new_classes migration). It was the subsequent publish invocations that failed (in spite of me not making any changes that would require any additional migration). But they failed only sometimes, which suggests that there is some kind of race condition or caching issue upstream.

[threepointone]

I'll have a fix for this later today. The api appears to have changed a little behaviour, and I have a fix for that. More concerning, like you mentioned, is that it's not a uniform error. I'll follow up on that internally.