tests/test-ui-color.py.out

check-code: allow command substitution with $(command)

Both `command` and $(command) are specified by POSIX. The latter nests
better. I don't see why we shouldn't allow both (or only the latter).

Differential Revision: https://phab.mercurial-scm.org/D6789

warning
error
b'buffered\n'
colored? True
colored? True