bug#44151: trmap: remote gdb with ssh doesn't work

[William Xu]

Hi,

I tried to run the debug remote program with gdb via ssh. I followed the
instructions from the [[info:tramp#Remote processes][info:tramp#Remote 
processes]]:

,----
| 5.5.5 Running a debugger on a remote host
| -----------------------------------------
| 
| ‘gud.el’ provides a unified interface to symbolic debuggers (*note
| (emacs)Debuggers::).  TRAMP can run debug on remote hosts by calling
| ‘gdb’ with a remote file name:
| 
|      M-x gdb <RET>
|      Run gdb (like this): gdb -i=mi /ssh:host:~/myprog <RET>
`----

However, after the program to debug is read, it looks like there is some
error setting up gdb's inferior tty?

---------------------------------8<------------------------------------- 
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /home/wx/tmp/a.out...

Debugger entered--Lisp error: (wrong-type-argument "consp nil")
  signal(wrong-type-argument ("consp nil"))
  tramp-signal-hook-function(wrong-type-argument (consp nil))
  signal(wrong-type-argument (consp nil))
  tramp-sh-handle-make-process(:name "gdb-inferior" :buffer #<buffer limbo<3>> 
:command nil :stderr nil :noquery nil :file-handler t)
  apply(tramp-sh-handle-make-process (:name "gdb-inferior" :buffer #<buffer 
limbo<3>> :command nil :stderr nil :noquery nil :file-handler t))
  tramp-sh-file-name-handler(make-process :name "gdb-inferior" :buffer #<buffer 
limbo<3>> :command nil :stderr nil :noquery nil :file-handler t)
  apply(tramp-sh-file-name-handler make-process (:name "gdb-inferior" :buffer 
#<buffer limbo<3>> :command nil :stderr nil :noquery nil :file-handler t))
  tramp-file-name-handler(make-process :name "gdb-inferior" :buffer #<buffer 
limbo<3>> :command nil :stderr nil :noquery nil :file-handler t)
  tramp-handle-start-file-process("gdb-inferior" #<buffer limbo<3>> nil)
  apply(tramp-handle-start-file-process ("gdb-inferior" #<buffer limbo<3>> nil))
  tramp-sh-file-name-handler(start-file-process "gdb-inferior" #<buffer 
limbo<3>> nil)
  apply(tramp-sh-file-name-handler start-file-process ("gdb-inferior" #<buffer 
limbo<3>> nil))
  tramp-file-name-handler(start-file-process "gdb-inferior" #<buffer limbo<3>> 
nil)
  apply(tramp-file-name-handler start-file-process "gdb-inferior" #<buffer 
limbo<3>> nil nil)
  start-file-process("gdb-inferior" #<buffer limbo<3>> nil)
  apply(start-file-process "gdb-inferior" #<buffer limbo<3>> nil nil)
  comint-exec-1("gdb-inferior" #<buffer limbo<3>> nil nil)
  comint-exec(#<buffer limbo<3>> "gdb-inferior" nil nil nil)
  make-comint-in-buffer("gdb-inferior" #<buffer limbo<3>> nil)
  gdb-inferior-io-mode()
  gdb-get-buffer-create(gdb-inferior-io)
  gdb-init-1()
  gdb-update()
  gdb("gdb -i=mi /ssh:wx@SERVER:/home/wx/tmp...")
  funcall-interactively(gdb "gdb -i=mi /ssh:wx@SERVER:/home/wx/tmp...")
  call-interactively(gdb record nil)
  command-execute(gdb record)
  execute-extended-command(nil "gdb" nil)
  funcall-interactively(execute-extended-command nil "gdb" nil)
  call-interactively(execute-extended-command nil nil)
  command-execute(execute-extended-command)
---------------------------------8<------------------------------------- 

I tested it with `-Q' by building the latest emacs in the git:

GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 
Version 10.14.6 (Build 18G6032)) of 2020-10-22

-- 
William