• Thanks to CapnCromulent who I happily copied VSCProxy from :)

NOTE: Remember to generate the sln file. To do that in Unity 5, run Assets -> Open C# Project

To use:

• Build or grab the pre-compiled RiderProxy app
• Make sure rider was installed at /usr/local/bin
• Point Unity External Editor to RiderProxy

To install:

• Build it or use the prebuilt package found in Builds (was compiled on Mac OSX 10.8 64-bit)
• Put VSCProxy.app wherever you want
• Make sure original Visual Studio Code.app is in the Applications folder
• Point Unity's External Editor setting at the Sublime Proxy app

Special thanks to:

• Tim Keating who got the barebones event handler setup
• Allan Lavell who did the heavy lifting for SublimeProxy (https://github.com/thinkrad/SublimeProxy)