;; Eval:
(setq load-prefer-newer t)
;; and then for example:
(delete-selection-mode t)

results in an error and the following in the *Messages* buffer:

insert-file-contents: Recursive load:
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/jka-compr.el.gz",
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/emacs-lisp/debug.el.gz",
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/jka-compr.el.gz",
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/jka-compr.el.gz",
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/jka-compr.el.gz",
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/jka-compr.el.gz",
"c:/MSys64/MingW64/share/emacs/26.0.50/lisp/delsel.el.gz"


In GNU Emacs 26.0.50 (build 5, x86_64-w64-mingw32)
 of 2017-08-04 built on LOBSANG
Repository revision: 6127f5901726740dad461b7b08c0095a65c737d5
Windowing system distributor 'Microsoft Corp.', version 10.0.16251
Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
about-emacs: Wrong type argument: number-or-marker-p, nil
Type C-x 1 to delete the help window.

Configured using:
 'configure --prefix=/MingW64 --with-jpeg --with-xpm --with-png
 --with-tiff --with-rsvg --with-xml2 --with-gnutls --with-imagemagick
 --without-dbus --enable-checking=no 'CFLAGS=-I/mingw64/include
 -fomit-frame-pointer -O3 -g0 -mtune=corei7' CPPFLAGS=-I/mingw64/include
 LDFLAGS=-L/mingw64/lib'

Configured features:
JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS

Important settings:
  value of $LANG: fr_FR
  locale-coding-system: cp1252

Major mode: Lisp Interaction

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:
(shadow sort mail-extr emacsbug message subr-x puny seq byte-opt gv
bytecomp byte-compile cconv dired dired-loaddefs format-spec rfc822 mml
mml-sec password-cache epa derived epg epg-config gnus-util rmail
rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils apropos help-fns radix-tree help-mode
easymenu cl-loaddefs cl-lib time-date mule-util tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp
disp-table term/w32-win w32-win w32-vars term/common-win 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 w32notify w32 multi-tty
make-network-process emacs)

Memory information:
((conses 16 101172 9279)
 (symbols 56 20314 1)
 (miscs 48 54 140)
 (strings 32 30898 815)
 (string-bytes 1 803193)
 (vectors 16 14252)
 (vector-slots 8 485738 7358)
 (floats 8 56 88)
 (intervals 56 898 13)
 (buffers 992 13))