Change use of global sys.stdout, sys.stdin os.environ to a hgrequest object. Note: also change hgrequest.write(str(thing)) to hgrequest.write(thing), people should make sure they write strings.

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m test -d "0 0"
hg history
hg manifest
hg cat a
hg verify