bug#12358: 24.2; M-x gud-gdb on remote binary does not work

[Paul K]

How to reproduce the problem:

prompt$ emacs --eval '(toggle-debug-on-error)'

then within emacs visit directory with some binary You want to debug
on some remote machine (my remote machine is running RH6, but
it probably does not matter) and issue:

M-x gud-gdb: theBinary

You will receive following error:
Debugger entered--Lisp error: (void-variable gdb-active-process)
  (if gdb-active-process "Continue" "Run")


Please DO NOT try to issue `M-x gdb` before, because this hides the problem.

Following are the data produced by M-x report-emacs-bug:


In GNU Emacs 24.2.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.4.2)
 of 2012-09-05 on blackCat
Windowing system distributor `The X.Org Foundation', version 11.0.11103000
Configured using:
 `configure '--with-x-toolkit=gtk3''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Debugger

Minor modes in effect:
  shell-dirtrack-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<return> <next> <down> <down> <down> <down> <down>
<escape> x g d b <backspace> <backspace> <backspace>
g u d - g d b <return> <escape> <backspace> . / r t
m <return> <escape> x r e p o r t - e m a <tab> <r
eturn>

Recent messages:
Debug on Error enabled globally
Tramp: Opening connection for Remote-Host using scpc...

Opening connection for Remote-Host using scpc... \
Tramp: Opening connection for Remote-Host using scpc...done
Tramp: Opening connection for Remote-Host using scpc...

Opening connection for Remote-Host using scpc... \
Tramp: Opening connection for Remote-Host using scpc...done
Entering debugger...

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rfc822 mml easymenu mml-sec
mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils
mailheader sendmail rfc2047 rfc2045 ietf-drums mail-utils debug gud
easy-mmode dired tramp-cache tramp-sh tramp tramp-compat auth-source
eieio byte-opt bytecomp byte-compile cconv macroexp assoc gnus-util
mm-util mail-prsvr password-cache shell pcomplete comint ansi-color ring
format-spec advice help-fns advice-preload tramp-loaddefs regexp-opt
cus-start cus-load time-date tooltip ediff-hook vc-hooks lisp-float-type
mwheel x-win x-dnd tool-bar dnd fontset image fringe lisp-mode register
page menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock
font-lock syntax facemenu font-core frame cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew
greek romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs
button faces cus-face files text-properties overlay sha1 md5 base64
format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process dbusbind dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)