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

hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "0 0"
touch b
hg add b
rm b
hg commit -A -m"comment #1" -d "0 0"