How to debug RimWorld from Visual Studio - Mhburg/AwsomeInventory GitHub Wiki

Environment: Visual Studio Community 2019+, Unity Tools for Visual Studio

Steps

  1. Install Visual Studio Community 2019 or better and choose workload for developing with Unity. If VS is already installed, please refer to Visual Studio tool for Unity
  2. Download Unity-debugging-2019.x.zip from dnSpy. More information can be found on its wiki.
  3. For the moment, you will have to follow this tutorial to acquire a debug build dll for unity
  4. Backup RimWorld folder. More specifically, backup the dll below,
 📁---Installation_path_of_RimWorld
 |    📁---RimWorld
 |         📁---MonoBleedingEdge
 |              📁---EmbedRuntime
 |                   ⚙️---mono-2.0-bdwgc.dll
  1. Unzip the file from dnSpy, copy the mono-2.0-bdwgc.dll in folder unity-2019.1.8 or newer version and drop it in the directory in step 3 to replace the vanilla one.
  2. Add RimWorld.exe as an existing project to solution as such.
  3. Right click on the added RimWorld.exe and add environment variable
    Variable=dnspy_unity_dbg2, Value=--debugger-agent=transport=dt_socket,server=y,address=127.0.0.1:56000,suspend=y,no-hide-debugger. And set it as the startup project via the right-click context menu.
  4. Update the build information of your project and have it produce "Portable" debugging information. Uncheck "Optimize Code" if it is checked. Example
  5. Almost there. Now, build the solution, start it without debugging. The default hotkey is "Ctrl+F5". And nothing will happen until a unity debugger is attached. Press "Attach Unity Debugger", click "Input IP" on the pop up window and "OK". RimWorld now will spin up with a debugger attached. Example

Tips

  • If RimWorld is installed through Steam, start Steam before the debug session, otherwise, there will be loading errors related to not found mods.
  • Don't forget to build your solution and copy the pdb files along with the dll files to mod folders.
  • If the game is patched with a transpiler written with Harmony. There is a chance that transpiler could throw an exception given the replaced runtime might emit different IL code than the original one.
  • At times, when a break point is set, it reads the break point will not currently be hit. Make sure symbols are loaded, check it in Debug->Window->Module. It could show the warning even though symbols are loaded. Don't worry, VS is not exactly working seamlessly with an Mono runtime in an out-of-process debug session. Just ignore the message and the code will hit the break point.