Deprecated APIs in Drupal 9.0.x core

A key goal of Drupal 9 is to remove deprecated APIs. Tracking the removal of them based on @deprecated and E_USER_DEPRECATED mentions, until the planned beta date on the week of March 2, 2020.

All projects by fixability

Ideally projects with no problems found would increase, while every other type of project would decrease as time goes on.

All project errors by fixability

Errors in all categories may be decreasing but errors not yet cleanly fixable will likely not decrease for a while.

Top 15 errors across all projects

These top errors originally accounted for almost two thirds of all deprecated API use. Fixing them across projects would solve most Drupal 9 compatibility gaps.