bug#31469: 27.0.50; Emacs crashes violently when `~/.emacs' does not set `package-selected-packages' and `list-packages' is run

[Jared Flatow]

Compile for OS X `--without-ns`.
Remove any definition of `package-selected-packages` from `~/.emacs'.
Run `emacs' (without `-Q`, so it will load `~/.emacs').
Run `M-x list-packages` within emacs.

It then reliably aborts trap for me (anecdotally, tested against
emacs-26.1-rc1 and emacs-25.3 tags as well).


Fatal error 6: Abort trap
Backtrace:
0   emacs                               0x00000001000b6a92 emacs_backtrace + 322
1   emacs                               0x00000001000990de 
terminate_due_to_signal + 110
2   emacs                               0x00000001000b65f6 
deliver_fatal_thread_signal + 134
3   libsystem_platform.dylib            0x00007fff8f899b3a _sigtramp + 26
4   ???                                 0x000000010d01cb4d 0x0 + 4513188685
5   ???                                 0x000000010d027464 0x0 + 4513231972
6   ???                                 0x000000010d002793 0x0 + 4513081235
7   ???                                 0x000000010d00289e 0x0 + 4513081502
8   libdyld.dylib                       0x00007fff8f686282 dyld_stub_binder + 
282
9   emacs                               0x00000001001aa0e8 letters + 7832
10  emacs                               0x00000001000b6e9f set_file_times + 47
11  emacs                               0x00000001000ceaae Fcopy_file + 1214
12  emacs                               0x000000010011acb1 funcall_subr + 353
13  emacs                               0x000000010011a138 Ffuncall + 792
14  emacs                               0x0000000100157854 exec_byte_code + 1924
15  emacs                               0x000000010011a09a Ffuncall + 634
16  emacs                               0x0000000100157854 exec_byte_code + 1924
17  emacs                               0x000000010011a09a Ffuncall + 634
18  emacs                               0x0000000100157854 exec_byte_code + 1924
19  emacs                               0x000000010011a09a Ffuncall + 634
20  emacs                               0x0000000100157854 exec_byte_code + 1924
21  emacs                               0x000000010011a09a Ffuncall + 634
22  emacs                               0x0000000100157854 exec_byte_code + 1924
23  emacs                               0x000000010011a09a Ffuncall + 634
24  emacs                               0x0000000100157854 exec_byte_code + 1924
25  emacs                               0x000000010011a09a Ffuncall + 634
26  emacs                               0x0000000100157854 exec_byte_code + 1924
27  emacs                               0x000000010011a09a Ffuncall + 634
28  emacs                               0x0000000100157854 exec_byte_code + 1924
29  emacs                               0x000000010011a09a Ffuncall + 634
30  emacs                               0x0000000100157854 exec_byte_code + 1924
31  emacs                               0x000000010011a09a Ffuncall + 634
32  emacs                               0x0000000100157854 exec_byte_code + 1924
33  emacs                               0x000000010011a09a Ffuncall + 634
34  emacs                               0x0000000100157854 exec_byte_code + 1924
35  emacs                               0x000000010011a09a Ffuncall + 634
36  emacs                               0x0000000100157854 exec_byte_code + 1924
37  emacs                               0x000000010011a09a Ffuncall + 634
38  emacs                               0x000000010011a85c call1 + 44
39  emacs                               0x0000000100124388 mapcar1 + 520
40  emacs                               0x000000010012451b Fmapcar + 251
...
Abort trap: 6

In GNU Emacs 27.0.50 (build 1, x86_64-apple-darwin16.7.0)
 of 2018-05-15 built on jflatow-pro
Repository revision: bb97552784af2e3cd89f0268b52ded0ae59e3895
System Description:  Mac OS X 10.12.6

Recent messages:
Checking /Users/jflatow/.emacs.d/lisp...
Done (Total of 0 files compiled)
For information about GNU Emacs and the GNU system, type C-h C-a.
You can run the command ‘list-packages’ with M-x l-pac RET
Package refresh done
11 packages can be upgraded; type ‘U’ to mark them for upgrading.

Configured using:
 'configure --without-makeinfo --without-ns'

Configured features:
JPEG NOTIFY ACL GNUTLS LIBXML2 ZLIB THREADS

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

Major mode: Package Menu

Minor modes in effect:
  show-paren-mode: t
  delete-selection-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:

Features:
(shadow sort mail-extr emacsbug sendmail mm-archive message dired
dired-loaddefs format-spec rfc822 mml mml-sec epa derived epg gnus-util
rmail rmail-loaddefs mailabbrev gmm-utils mailheader mm-decode mm-bodies
mm-encode mail-utils network-stream starttls url-http tls gnutls
mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr url-gw
nsm rmc puny url-cache url-auth url url-proxy url-privacy url-expand
url-methods url-history url-cookie url-domsuf url-util mailcap
term/xterm xterm elec-pair cc-styles cc-align cc-engine cc-vars cc-defs
time-date paren delsel edmacro kmacro compile comint regexp-opt
ansi-color ring mule-util dash-autoloads info tool-bar finder-inf
package easymenu epg-config url-handlers url-parse auth-source cl-seq
eieio eieio-core cl-macs eieio-loaddefs password-cache json map url-vars
seq byte-opt gv bytecomp byte-compile cconv cl-loaddefs cl-lib tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select mouse
jit-lock font-lock syntax facemenu font-core term/tty-colors frame
cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai
tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian
slovak czech european ethiopic indian cyrillic chinese composite
charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev
obarray minibuffer cl-preloaded 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 kqueue
multi-tty make-network-process emacs)

Memory information:
((conses 16 866277 67018)
 (symbols 48 27499 1)
 (miscs 40 49 161)
 (strings 32 96632 7001)
 (string-bytes 1 2399032)
 (vectors 16 32265)
 (vector-slots 8 1359075 140202)
 (floats 8 54 471)
 (intervals 56 109250 2789)
 (buffers 992 13))