Path: utzoo!utgpu!water!watmath!clyde!ima!bbn!jr@bbn.com
From: jr@bbn.com (John Robinson)
Newsgroups: comp.emacs
Subject: Re: The impossible happens - SIGIOT on Sun-3
Summary: It's emacs' way to die
Message-ID: <26464@bbn.COM>
Date: 1 Jul 88 15:31:08 GMT
References: <23550@teknowledge-vaxc.ARPA>
Sender: news@bbn.COM
Reply-To: jr@bbn.com (John Robinson)
Organization: BBN Laboratories Incorporated, Cambridge MA
Lines: 17
In-reply-to: mkhaw@teknowledge-vaxc.ARPA (Mike Khaw)

In article <23550@teknowledge-vaxc.ARPA>, mkhaw@teknowledge-vaxc (Mike Khaw) writes:
>We have a user (no, really, it wasn't me) who got a core dump with a
>message about "IOT instruction" while running GNU Emacs 18.41 on a Sun
>3/50 running SunOS 3.5.

When emacs reaches an impossible condition, it calls the C library
function abort.  If you look at abort(3), you'll see that it generates
a SIGIOT signal, which causes emacs to core dump.

To debug it, run dbx (or your favorite debugger) on the core file and
look at the stack.  Have the source handy.

I encountered an abort running under X11.  But since the X11 code
originated about version 18.49, I assume you aren't.

You might want to try to get the current distribution.
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