Hi, Recently I had to switch from ghc 6.12.3 to ghc 7.0.1 because of the bug #4235. This switch has introduced a problem with one of third-party libraries I use ('satchmo', an interface for SAT solvers). The problem is that writing to stdin of a process started by System.Process.runInteractiveCommand silently fails provided it's stderr is not read. If stderr of the spawned process is redirected to /dev/null or fully read by the parent process, then problem does not come up. The troubled code is available at http://bit.ly/dNwrIV (lines 43-45). Changes between versions of the 'process' library (1.0.1.3 -> 1.0.1.4) bundled with ghc 6.12.3 and 7.0.1 only include one bug fix, which is not the source of the problem described, as far as I can understand. The problem is not present with ghc 6.12.* at all. Something has definitely changed between these two ghc versions. Since I've spent considerable amount of time on finding a workaround for the problem, I'd like to file a real bug report, but I'm not completely sure where to do it because there are several pieces of software involved (ghc itself, 'process', 'satchmo' and 'minisat2' SAT solver). Could somebody guide me please?