Re: zsh bug-hang on startup after exec

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxxxxxxxxx>]

On Mar 21,  1:25pm, Ryan Richter wrote:
} Subject: zsh bug-hang on startup after exec
}
} I had been using bash as my login shell, and had it set up to exec
} zsh. I just upgraded zsh from 3.1.6 to 3.1.9, and when I log in, zsh
} hangs immediately after being execed, before it even processes the
} startup scripts.

The strace output shows that it's getting stuck in this loop in init.c:

            while ((ttpgrp = gettygrp()) != -1 && ttpgrp != mypgrp) {
                sleep(1);       /* give parent time to change pgrp */
                mypgrp = GETPGRP();
                if (mypgrp == mypid)
                    attachtty(mypgrp);
                if (mypgrp == gettygrp())
                    break;
                killpg(mypgrp, SIGTTIN);
                mypgrp = GETPGRP();
            }

Why zsh is not becoming the process group leader, I don't know.  Obviously
bash must be exec'ing it before making *itself* the process group leader,
but then who *is* the group leader, a?

Note that

getpid()                                = 20122
getpgrp()                               = 20120
ioctl(10, TIOCGPGRP, [20121])           = 0

So there are at least three processes involved here ... the process group
leader is 20120 (whatever that was), but the tty group leader is 20121,
and neither of those is zsh (20122), so (mypgrp == mypid) is never going
to be true.

} Anyway, this is a linux 2.2.19 i686 system with glibc 2.1.3, and zsh was
} compiled with egcs 1.1.2.

Why does everyone always identify their Linux system by kernel version and
glibc version?  That's almost never enough information.  The vendor (e.g.
redhat) and vendor's version number (e.g. 7.1) are almost always much more
useful.  In this case it'd also be nice to know how you're logging in; is
it on the text console?  Remote shell?  XDM console?  If the latter, are
you using vanilla XDM, KDE, Gnome, or something else?

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net