I wonder how to fix it. Merely documenting the restriction isn't really anoption, as no widespread system has it. Saving the signal handler,disabling it then restoring would work but introduces a slight race condition (a child process can exit while we're in grantpt()).
In fact, it is documented: http://pubs.opengroup.org/onlinepubs/9699919799/functions/grantpt.html The behavior of the grantpt() function is unspecified if the application has installed a signal handler to catch SIGCHLD signals. What is the real package, which hits this problem ? Petr