[PATCH 3 of 3 v3] demandimport: reject contextlib._GeneratorContextManager on Py < 3.2

Yuya Nishihara yuya at tcha.org
Mon Sep 26 10:09:02 EDT 2016


On Wed, 21 Sep 2016 19:09:34 +0000, timeless wrote:
> # HG changeset patch
> # User timeless <timeless at mozdev.org>
> # Date 1474429683 0
> #      Wed Sep 21 03:48:03 2016 +0000
> # Node ID 0070696439eab002f6dd32bcb40eb671daff800a
> # Parent  adb54fd7d90f0ca607432ed7ae884da55ec427de
> # Available At https://bitbucket.org/timeless/mercurial-crew
> #              hg pull https://bitbucket.org/timeless/mercurial-crew -r 0070696439ea
> demandimport: reject contextlib._GeneratorContextManager on Py < 3.2
> 
> decorator expects:
>  from contextlib import _GeneratorContextManager
> to throw an exception on python < 3.2 (issue5373).
> 
> We tell demandimport to throw it.
> 
> diff -r adb54fd7d90f -r 0070696439ea mercurial/demandimport.py
> --- a/mercurial/demandimport.py	Wed Sep 21 18:58:54 2016 +0000
> +++ b/mercurial/demandimport.py	Wed Sep 21 03:48:03 2016 +0000
> @@ -313,6 +313,12 @@
>  if os.name != 'nt':
>      reject('distutils', 'msvc9compiler', ImportError, 'No module named _winreg')
>  
> +# decorator imported by ipython from pygments does an import which isn't
> +# friendly to demandimport.
> +if sys.version_info[0] < 3 or sys.version_info[1] < 2:
> +    reject('contextlib', '_GeneratorContextManager',
> +           ImportError, 'cannot import name _GeneratorContextManager')

I'm not a fan of duplicating knowledge about module internals unless there's
a measurable win. We could break the current "ignore" list down to fine-tuned
"rejects" rules, but that would end with bloated set of rules we wouldn't
want to maintain.


More information about the Mercurial-devel mailing list