@glyph I've had success debugging with debugpy and vscode. (debugpy: https://github.com/microsoft/debugpy ) I believe it was created for debugging functionality in vscode, but it uses an open protocol that other tools have been built to support as well, (though I haven't tried any of them.)
Tools that support the Debug Adapter Protocol are listed on this webpage: https://microsoft.github.io/debug-adapter-protocol/