On windows 8, tup doesn't seem to attach itself properly to spawned processes. Even the most simple test cases fail (see attached gist). This must be the real culprit behind my recent reopening of #80.
git clone git://gist.github.com/3683701.git twin8 && cd twin8 && tup init && tup upd
*** tup errors ***
tup error: Expected to write to file 'input.txt.out' from cmd 20 but didn't
*** Command ID=20 ran successfully, but tup failed to save the dependencies.
[ ] 100%
*** tup: 1 job failed.