https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=2232498c712acc97a38fdc297cbe53ba74d0ec2c
commit 2232498c712acc97a38fdc297cbe53ba74d0ec2c Author: Corinna Vinschen <corinna-cyg...@cygwin.com> Date: Thu Jul 25 10:40:03 2019 +0200 Cygwin: Don't change pgid to ctty pgid under debugger _pinfo::set_ctty sets myself's pgid to the ctty pgid if the process has been started from a non-Cygwin process. This isn't the right thing to do when started from GDB. GDB starts the application via standard Windows means, not via Cygwin fork/exec, so it's treated as being a non-Cygwin parent. But we want the app running in it's own process group. So skip this step when running under a debugger Signed-off-by: Corinna Vinschen <corinna-cyg...@cygwin.com> Diff: --- winsup/cygwin/pinfo.cc | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc index cdbd8bd..123784e 100644 --- a/winsup/cygwin/pinfo.cc +++ b/winsup/cygwin/pinfo.cc @@ -554,7 +554,11 @@ _pinfo::set_ctty (fhandler_termios *fh, int flags) syscall_printf ("attaching %s sid %d, pid %d, pgid %d, tty->pgid %d, tty->sid %d", __ctty (), sid, pid, pgid, tc.getpgid (), tc.getsid ()); if (!cygwin_finished_initializing && !myself->cygstarted - && pgid == pid && tc.getpgid () && tc.getsid ()) + && pgid == pid && tc.getpgid () && tc.getsid () + /* Even GDB starts app via CreateProcess which changes cygstarted. + This results in setting the wrong pgid here, so just skip this + under debugger. */ + && !being_debugged ()) pgid = tc.getpgid (); /* May actually need to do this: