Version 4.1.0-3 of mpfr4 is marked for autoremoval from testing on Thu 30 Jun 2022. It depends (transitively) on nvidia-graphics-drivers-tesla-470, affected by #1011146. You should try to prevent the removal by fixing these RC bugs.
Last update: 2022-05-25
Problems while searching for a new upstream version
uscan had problems while searching for a new upstream version:
In watchfile debian/watch, reading webpage
http://www.mpfr.org/mpfr-current/ failed: 500 Can't connect to www.mpfr.org:80 (Connection refused)