mypy --fast-parser option broken with 1.0.0

[sseg]

Running in a Python 3.6.0 virtual environment, running mypy with --fast-parser option does not work with typed-ast==1.0.0:

$ pip freeze | grep 'mypy\|typed-ast'
mypy-lang==0.4.6
typed-ast==1.0.0

$ mypy --fast-parser .
You must install the typed_ast package before you can run mypy with `--fast-parser`.
You can do this with `python3 -m pip install typed-ast`.

The same run works with typed-ast==0.6.3

[emmatyping]

mypy has moved to the mypy package name, and is at version 0.471, if you update mypy to 0.471, does that fix the issue?

[gvanrossum]

It's expected that mypy 0.47* doesn't work with typed-ast 1.0+.

…

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On Feb 16, 2017 12:21 PM, "Ethan" ***@***.***> wrote: mypy has moved to the mypy package name, and is at version 0.471, if you update mypy to 0.471, does that fix the issue? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#31 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACwrMu4eKa7xiYmAOTMoqH3PrEbpH7SBks5rdK_kgaJpZM4MDfQe> .

[ddfisher]

This is expected -- typed_ast made some backwards incompatible changes when updating to 1.0.

To fix, use mypy (no longer mypy-lang) version 0.471, which has an upper bound on the typed-ast version it installs. The next release of mypy will be out in a couple weeks and will be updated to work with typed-ast 1.0.

[sseg]

Resolved with the mypy package for me. Thanks all.

Leaving a link here to the blog post explaining the changes for anyone else coming across this: http://mypy-lang.blogspot.com/2017/01/mypy-0470-released.html