// pseudo-terminal.
	// - GO_TEST_TERMINAL_SIGNALS=1: This process creates a new process
	// group and session. The PTY is the controlling terminal for this
	// session. This process masks SIGTTOU, making it eligible to be a
	// foreground process group. This process will take over as foreground
	// from subprocess 2 (step 4 above).
	// - GO_TEST_TERMINAL_SIGNALS=2: This process create a child process