I personally won't consider using a language for a meaningful project unless it has a decent debugger, and reasonable refactoring; ie. at least find references & rename.
Beef is building on an IDE, which is a refreshing take, but it's still too early.
D in emacs works very well, but you'll have to put some work into it. Spacemacs (https://www.spacemacs.org/) makes the work a little easier, here's my .spacemacs file if anyone is interested https://gitlab.com/snippets/1942930
Using that .spacemacs file you should be able to launch a fully prepped for D! The only other dependencies are a D compiler and DCD (https://github.com/dlang-community/DCD) built and in your PATH. I'd be happy to answer any questions if something doesn't work.
Other IDEs with a languageserver implementation can make use of DLS https://github.com/d-language-server/dls. VSCode and sublime are two I've had good success with.. but I always end up back with emacs ;)
As for a debugger, you can debug any D program with GDB/LLDB (depending on if you compile with dmd/lcd). Then you can use any graphical debugger that uses gdb. Nemiver is my favorite, then there's a few web based ones that are nice: https://www.gdbgui.com/
https://wiki.dlang.org/Editors
Also had really good luck doing D with Spacemacs, but Spacemacs is a hit or miss to setup for me. Other times I just use Sublime Text for the syntax highlighting.
1. gdc or ldc on Debian. The experience /may/ be different with the dmd repositories, but being external they're of less interest to me.
You can also get soft copies (i.e. mobi, pdf) and the docs as part of the d-apt repository for debian.
Depending on the nature of distribution it is probably just in a different package (or the package maintainer needs yelling at).
Which leads me to wonder why we don't have dmd{,-doc} in Debian now, given it has been ~3 years since the compiler was open sourced. I can't even find an ITP in a quick search :/
dmd -man dman dman
There's some limited debugging support at the generated C code, but this is not sufficient for me.
There is also a D specific IDE which I can't remember the name of which is probably best if you just want something that works (it's pretty lightweight)