The gambit manual section 17.7.2 explains how to redirect stdout/stderr of child processes opened via `open-process` and siblings to the newly created port. That's the closest I could find to what I want to do: Run the child process and process return process the output when the child exits normally and raise an exception (containing what the child wrote to stderr) otherwise. I don't mind a few tricks. The fewer the better. But I need this on Linux and Windows, at least that it. But I don't see how to do that with Gambit. Thanks for any hint. /Jörg