I can recreate this error in "emacs -Q" after evaluating the below and then
doing M-x list-packages.

=====

(require 'package)
(add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/") t)

=====

Here is the error I get:

=====

Importing package-keyring.gpg...done
error in process filter: End of file during parsing

=====

As an additional request (hopefully minor), can this process filter error
be improved to give more info as to which file caused it?


In GNU Emacs 25.0.93.10 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.23)
 of 2016-05-02 built on
Repository revision: fd7b430afdd7ddea40cad7d231f634ff8bd536d8
Windowing system distributor 'The X.Org Foundation', version 11.0.60900000
System Description: Red Hat Enterprise Linux Workstation release 6.6
(Santiago)

Configured using:
 'configure --with-modules
 --prefix=/home/kmodi/usr_local/apps/6/emacs/emacs-25
 'CPPFLAGS=-fgnu89-inline -I/home/kmodi/usr_local/6/include
 -I/usr/include/freetype2 -I/usr/include' 'CFLAGS=-ggdb3 -O0'
 'CXXFLAGS=-ggdb3 -O0' 'LDFLAGS=-L/home/kmodi/usr_local/6/lib
 -L/home/kmodi/usr_local/6/lib64 -ggdb3'
 PKG_CONFIG_PATH=/home/kmodi/usr_local/6/lib/pkgconfig:/home/kmodi/usr_local/6/lib64/pkgconfig:/cad/adi/apps/gnu/linux/x86_64/6/lib/pkgconfig:/cad/adi/apps/gnu/linux/x86_64/6/lib64/pkgconfig:/usr/lib/pkgconfig:/usr/lib64/pkgconfig:/usr/share/pkgconfig:/lib/pkgconfig:/lib64/pkgconfig'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK2 X11 MODULES

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=none
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

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

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Mark set
current-kill: Kill ring is empty
Mark set
package
(("gnu" . "http://elpa.gnu.org/packages/") ("melpa" . "
http://melpa.org/packages/"))
Importing package-keyring.gpg...done
You can run the command ‘list-packages’ with M-x l-pac RET
error in process filter: End of file during parsing [2 times]
Mark set
next-line: End of buffer

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug sendmail mm-archive message dired
format-spec rfc822 mml mml-sec mailabbrev gmm-utils mailheader mm-decode
mm-bodies mm-encode url-handlers mail-utils network-stream nsm starttls
url-http tls gnutls mail-parse rfc2231 rfc2047 rfc2045 ietf-drums url-gw
url-cache url-auth url url-proxy url-privacy url-expand url-methods
url-history url-cookie url-domsuf url-util url-parse auth-source cl-seq
eieio eieio-core cl-macs gnus-util mm-util help-fns mail-prsvr
password-cache url-vars mailcap epg finder-inf package epg-config seq
byte-opt gv bytecomp byte-compile cl-extra help-mode easymenu cconv
cl-loaddefs pcase cl-lib time-date mule-util tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core 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 charscript case-table epa-hook jka-cmpr-hook help
simple abbrev 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
dbusbind inotify dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 122628 13965)
 (symbols 48 25171 0)
 (miscs 40 49 166)
 (strings 32 27533 18874)
 (string-bytes 1 736436)
 (vectors 16 16284)
 (vector-slots 8 478740 15323)
 (floats 8 238 375)
 (intervals 56 2149 362)
 (buffers 976 12)
 (heap 1024 35960 2589))

-- 

-- 
Kaushal Modi