The Read the Docs environment doesn't have SHELL defined. This causes
mach.mixin.process's import to fail, as it insists on finding an active
shell. While we could fix mach.mixin.process to not raise if the
variable is not set, this is a bit more work and has wider build system
and mach implications. So we employ a quick hack instead.
DONTBUILD (NPOTB)
--HG--
extra : commitid : 23fRi9TQht4
extra : rebase_source : 4b3d0833f789a73fee67c0cadcf525434f08f78b
202a3968b4