Bug#808422: xmonad should provide an upgrade path for user compiled xmonad from libff5 to libffi6

[Kari Pahula]

Package: xmonad
Version: 0.11.1-4
Severity: normal

I upgraded my laptop and couldn't startx after rebooting the system.
Starting X itself went okay but digging in to logs found this in my
.xsession-errors:

/home/kaol/.xmonad/xmonad-x86_64-linux: error while loading shared libraries: libffi.so.5: cannot open shared object file: No such file or directory

My .xsession is

#! /bin/sh

exec xmonad

/usr/bin/xmonad tries to execute my xmonad-x86_64-linux but linker
won't be able to since I no longer had libffi5 installed on my system.
Removing my xmonad-x86_64-linux solved the situation.  xmonad built me
a new xmonad-x86_64-linux and I could proceed as normal.

Looks like I hadn't needed to update my xmonad.hs in a while.  It
would be nice if xmonad would fail gracefully when a user's own xmonad
binary had gone stale.


-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.2.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=C, LC_CTYPE=fi_FI.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages xmonad depends on:
ii  libc6         2.21-4
ii  libffi6       3.2.1-4
ii  libgmp10      2:6.1.0+dfsg-2
ii  libx11-6      2:1.6.3-1
ii  libxext6      2:1.3.3-1
ii  libxinerama1  2:1.1.3-1+b1
ii  libxrandr2    2:1.5.0-1
ii  x11-utils     7.7+3

Versions of packages xmonad recommends:
pn  libghc-xmonad-dev  <none>
pn  libghc-xmonad-doc  <none>
ii  xfonts-base        1:1.0.4+nmu1

Versions of packages xmonad suggests:
pn  gnome-session-flashback  <none>
ii  suckless-tools [dmenu]   41-1

-- no debconf information