Track setup.ml before oasis 0.4 (compatibility with OPAM).
Open Printf and cut some lines to 80 chars.
Introduce a debug output for Mpp_actions.command
Revert e88bd0bd642263cbc07015ee59af7551d0a18c87

The redirection works well with dash (= /bin/sh on Linux).
Make sure external commands are executed by bash.