Bug#896019: libglib2.0-0: undefined symbol g_date_copy breaking many programs

[rektide de la faye]

Package: libglib2.0-0
Version: 2.56.1-2
Severity: grave
Justification: renders package unusable

Dear Maintainer,

I recently updated a number of packages on my Debian/testing laptop, via aptitude
and included in that upgrade to satisfy dependencies was libglib-2.0-0.

Since installing, many many programs on my system refuse to start. Trying
to run nmcli, for example, returns:

nmcli: symbol lookup error: /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined symbol: g_date_copy

I also see like errors trying to run lightdm, urxvt, vi.
This file appears to be a symlink, pointing at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.1.

There is a .4200.0 in that directory. I tried symlinking to that, but got a different set of undefined
symbol errors keeping me from running things- g_option_group_unref.

This does appear to gravely reduce the functionality of my workstation.

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (250, 'unstable'), (600, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.4.1
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/zsh

Versions of packages libglib2.0-0 depends on:
ii  libc6        2.27-3
ii  libffi6      3.2.1-4
ii  libmount1    2.30.2-0.1
ii  libpcre3     8.39-9
ii  libselinux1  2.6-3+b1
ii  zlib1g       2.8.dfsg-2+b1

Versions of packages libglib2.0-0 recommends:
ii  libglib2.0-data   2.56.1-2
ii  shared-mime-info  1.7-1
ii  xdg-user-dirs     0.15-2

libglib2.0-0 suggests no packages.

-- no debconf information