https://issues.dlang.org/show_bug.cgi?id=5299
--- Comment #7 from [email protected] --- Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/5ffc7d3784dc416769ff1a4aa0ab959ca42cd47e Fix Issue 5299 - Protected inheritance is semantically undefined Deprecation -> Error https://github.com/D-Programming-Language/dmd/commit/486e92da11fd567c32634a3085a31fa266634d77 Merge pull request #3911 from yebblies/issue5299 Issue 5299 - Turn base class protection into an error --
