bug#34566: 27.0.50; package-list-packages never finishes loading

[Jason Lewis]

if you run package-list-packages, emacs never finishes loading.
The status bar has "Loading" in it and if you press U, the messages
window gets "Waiting for refresh to finish..."

emacs -Q
M-x package-list-packages
press U





In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2019-02-17, unofficial emacs-snapshot build: http://emacs.ganneff.de/, git 
commit 6b7b85b60e76c5e867f77387e7c57d49f4c0a2cd built on 
runner-d40f5ff3-project-26-concurrent-0
Repository revision: 435ab9aee92fa54fef2a7dfef410953347a207e9
Repository branch: HEAD
Windowing system distributor 'The X.Org Foundation', version 11.0.11902000
System Description: Debian GNU/Linux 9 (stretch)

Recent messages:
Checking 24 files in /usr/share/emacs/27.0.50/lisp/cedet...
Checking 57 files in /usr/share/emacs/27.0.50/lisp/calendar...
Checking 87 files in /usr/share/emacs/27.0.50/lisp/calc...
Checking 107 files in /usr/share/emacs/27.0.50/lisp/obsolete...
Checking for load-path shadows...done
Auto-saving...done
Mark set
Type "q" in help window to restore its previous buffer.
Saving file /home/jason/emacs-setmail.el...
Wrote /home/jason/emacs-setmail.el

Configured using:
 'configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --with-pop=yes
 
--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/27.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/27.0.50/site-lisp:/usr/share/emacs/site-lisp
 --build x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
 --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes
 
--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/27.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/27.0.50/site-lisp:/usr/share/emacs/site-lisp
 --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars
 'CFLAGS=-g -O2
 
-fdebug-prefix-map=/builds/joerg/emacs/stretch_amd64/emacs-snapshot-20190216+emacs-26.1-4194-g6b7b85b60e=.
 -fstack-protector-strong
 -Wformat -Werror=format-security -Wall -fno-omit-frame-pointer'
 'CPPFLAGS=-Wdate-time -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB
NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF
XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS PDUMPER LCMS2 GMP

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

Major mode: Emacs-Lisp

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-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

Load-path shadows:
None found.

Features:
(cl-extra cl-print thingatpt help-fns radix-tree smtpmail help-mode pp
shadow sort mail-extr emacsbug message dired dired-loaddefs format-spec
rfc822 mml mml-sec epa derived gnus-util rmail rmail-loaddefs time-date
mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader sendmail
mail-utils cus-edit cus-start cus-load wid-edit gnutls network-stream
url-http 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 epg 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 elec-pair mule-util tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar 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 threads dbusbind inotify lcms2 dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 16 155051 36448)
 (symbols 48 9699 7)
 (strings 32 36978 1524)
 (string-bytes 1 963016)
 (vectors 16 14935)
 (vector-slots 8 181902 19196)
 (floats 8 33 116)
 (intervals 56 8269 171)
 (buffers 992 15))