Version 0.6-1 of mpl-scatter-density is marked for autoremoval from testing on Tue 07 Jan 2020. It depends (transitively) on fast-histogram, affected by #945413. You should try to prevent the removal by fixing these RC bugs.
Last update: 2019-12-05
Standards version of the package is outdated.
The package should be updated to follow the last version of Debian Policy
(Standards-Version 4.4.1 instead of