Hey @dep! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite.

As a workaround, you can remove all @babel/* entries from the lock files and try install again. Or you can run yarn dedupe or npm dedupe, which depends on the package manager you use.

The culprit is that there are multiple @babel/traverse in the node_modules and the old babel/traverse can not provide the new babel/traverse method required by some plugins. If there are only one @babel/traverse copy, it should just work.

While we are trying our best to maintain compatibility issues between multiple Babel library versions, as a user running deduplicate on your dependencies can effectively help you dodge such issues.

That requeueComputedKeyAndDecorators is very interesting, since it comes from inside @babel/traverse which is the same package that defines the function (so it should be defined). Do you happen to have a repository that reproduces the problem?

@nicolo-ribaudo The path instance here was created by the old @babel/traverse (depended by the @babel/core), then we pass that path to the new @babel/traverse (depended by @babel/plugin-transform-async-generator-functions) 's visitors.environmentVisitor, so the Path.requeueComputedKeyAndDecorators is undefined.

Currently our e2e test can not catch such errors because we reduce every @babel/* version down to their earliest, which is still not duplicated. To catch this we will have to manually introduce different copies in node_modules.

I suggest we release a 7.25 update for @babel/core as well, so that it is easier for people to upgrade the root @babel/traverse.