On 2016-07-16 05:53, Stefan Monnier wrote:
> % src/emacs -Q -l elpa/packages/nhexl-mode/nhexl-mode.el lisp/subr.el -f
> nhexl-mode
> 
> And then do C-v enough times (about 10 times) gives me an assertion
> violation

I'm not seeing in GNU Emacs 25.1.50.3 (x86_64-pc-linux-gnu, GTK+ Version 3.18.9)
 of 2016-07-16 built on clem-w50-mint
Repository revision: 867041f9c6f713a4c73cfbf467e9ceee79a6214a
Windowing system distributor 'The X.Org Foundation', version 11.0.11803000
System Description:	Linux Mint 18 Sarah

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Nhexl mode enabled in current buffer
Quit [2 times]
Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 LIBSYSTEMD

Important settings:
  value of $LC_MONETARY: en_DK.UTF-8
  value of $LC_NUMERIC: en_DK.UTF-8
  value of $LC_TIME: en_DK.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix