D117: run-tests: warn if --color=always and no pygments installed

[yuja (Yuya Nishihara)]

yuja added inline comments.

INLINE COMMENTS

> run-tests.py:427
> +                             'pygments is not installed\n')
>  
>      global useipv6

Nit: missing space after "because".

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D117

EMAIL PREFERENCES
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To: martinvonz, #hg-reviewers
Cc: yuja, mercurial-devel