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 a
cd a
echo a > foo
hg add foo
hg commit -m 1 -d "0 0"
rm foo
hg remove foo
hg commit -m 2 -d "0 0"

cd ..
hg clone a b