And a Windows/Docker issue to throw into the mix: for some reason, Meltano in the same Docker container it works well in on Mac (and fwiw used to on Windows as well?) complains that it doesn't know what

tap-mysql

is:

=> ERROR [6/6] RUN meltano install                                                                                                                                                                                                                                                                                 9.6s
------
 > [6/6] RUN meltano install:
#0 7.353 Extractor 'tap-mysql' is not known to Meltano. Try running `meltano lock --update --all` to ensure your plugins are up to date.

Any suggestions as to why Meltano would suddenly lose track of a well-defined plugin? (This is the Transferwise option:

plugins:
  extractors:
  - name: tap-mysql
    variant: transferwise
    pip_url: pipelinewise-tap-mysql

As I mentioned, works well in other environments.) Could this be an issue with network access inside of Docker?

As you may have already figured out,

.lock

files are required in 3.0: https://docs.meltano.com/guide/v3-migration/#plugin-lock-files-are-now-always-required

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