When I run gdb on a remote host through tramp I get the following
warning in the input/output buffer:

"warning: GDB: Failed to set controlling terminal: Operation not
permitted\n"

Tramp is defaulting to a scp connection to the remote server on which
I'm running gdb.

I still got it with emacs -q so it definetly not caused by any external
packages. It seems bug#4604 and bug#6360 are similar to this but I
couldn't find any resolution to these and it has been awhile since these
were submitted.

In GNU Emacs 24.5.1 (x86_64-apple-darwin13.4.0, NS apple-appkit-1265.21)
 of 2015-04-10 on builder10-9.porkrind.org
Windowing system distributor `Apple', version 10.3.1404
Configured using:
 `configure --with-ns '--enable-locallisppath=/Library/Application
 Support/Emacs/${version}/site-lisp:/Library/Application
 Support/Emacs/site-lisp''

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Debugger

Minor modes in effect:
  gdb-many-windows: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  electric-indent-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 messages:
Tramp: Checking `vc-registered' for /scp:andrew:/afs/
andrew.cmu.edu/usr4/akyle/private/213/bomb/bomb.c...done
Tramp: Inserting `/scp:andrew:/afs/
andrew.cmu.edu/usr4/akyle/private/213/bomb/bomb.c'...done
Switched to thread 1
Switched to thread nil
Undefined command: "ls".  Try "help".
End of buffer
Undefined command: "ls".  Try "help".
Switched to thread 1
Making completion list... [2 times]
call-interactively: End of buffer [3 times]

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mail-utils cus-start cus-load
cc-langs cc-mode cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align
cc-engine cc-vars cc-defs gdb-mi bindat json gud easy-mmode dired
tramp-cache tramp-sh tramp tramp-compat auth-source eieio byte-opt
bytecomp byte-compile cl-extra cl-loaddefs cl-lib cconv eieio-core
gnus-util mm-util mail-prsvr password-cache tramp-loaddefs trampver
shell pcomplete comint ansi-color ring format-spec advice help-fns
help-mode easymenu time-date tooltip electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment lisp-mode prog-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 nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process cocoa ns
multi-tty emacs)

Memory information:
((conses 16 153830 10968)
 (symbols 48 24590 0)
 (miscs 40 169 224)
 (strings 32 33803 3614)
 (string-bytes 1 1066376)
 (vectors 16 17496)
 (vector-slots 8 501946 5953)
 (floats 8 337 357)
 (intervals 56 996 30)
 (buffers 960 29))