How does the 64bits time_t transition work?

[Detlef Vollmann <dv@vollmann.ch>]

Is there a description anywhere how the 64bit time transition works?
I'm currently stuck with a hard to maintain Sid system.
It currently has "871 not upgraded" and it's nearly impossible to
install new packages.

I've looked e.g. into gnutls (on amd64), and libgnutls30t64 (3.8.3-1.1)
as well as libgnutls30 (3.8.3-1) both install
/usr/lib/x86_64-linux-gnu/libgnutls.so.30.37.1.
Does the new libgnutls.so.30.37.1 provide both ABIs?

  Detlef