Matt Harbison <matt_harbison@yahoo.com> [Sat, 12 Oct 2019 22:21:51 -0400] rev 43194
hghave: use a native string to invoke the `black` command
Windows can't create a process based on bytes. Apparently only the output test
in `matchoutput` wants bytes.
Differential Revision: https://phab.mercurial-scm.org/D7080