revit-addin-debugging

# Revit Add-in Debugging The `Nice3point.Revit.Sdk` makes the IDE's start-debugging action launch Revit and attach the debugger, without a `launchSettings.json`. Deploy the add-in first (`revit-addin-publishing`); the launched Revit loads the deployed build. ## When to use - Setting up a project where a debug session starts the right Revit version and breaks in the add-in. - Pointing the launcher at a non-default Revit install or start arguments. - Keeping iterative debugging and Hot Reload responsive. ## When not to use - The build never needs to run under a debugger — plain `DeployAddin` copying is enough (`revit-addin-publishing`). ## Workflow ### Step 1: Enable launch ```xml <LaunchRevit>true</LaunchRevit> ``` The SDK sets `StartAction=Program`, `StartProgram` to `C:\Program Files\Autodesk\Revit $(RevitVersion)\Revit.exe`, and `StartArguments=/language ENG`; the IDE reads them, starts Revit, and attaches the debugger. Enable it in the manifest-owning project alongside `DeployAddin`; each build deploys before launch. ### Step 2: Override the target when the defaults are wrong ```xml <StartProgram>D:\Autodesk\Revit $(RevitVersion)\Revit.exe</StartProgram> <StartArguments>/language CHS</StartArguments> ``` Set these when Revit is installed off the default path, or when forcing a language or opening a model on start. ### Step 3: Keep Hot Reload working Repacking (`IsRepackable`) merges dependencies as a post-build step that rewrites the output assembly; it defeats Hot Reload and slows the edit–run loop. For local debugging on Revit 2027+, leave `IsRepackable` off and rely on manifest-level isolation (`revit-dependency-isolation`); reserve repacking for release builds on pre-2027 versions. ### Step 4: Verify Set a breakpoint in a command, start a debug session, and confirm the matching Revit launches, loads the add-in, and stops at the breakpoint. ## Validation - [ ] `LaunchRevit` is enabled in the manifest-owning project, alongside `DeployAddin`. - [ ] `StartProgram`/`StartArguments` are overridden only when the defaults do not fit. - [ ] `IsRepackable` is off for debug builds; isolation covers dependency conflicts. ## Common Pitfalls | Pitfall | Correct approach | |------------------------------------------------------|------------------------------------------------------------------------------| | Looking for a `launchSettings.json` | The SDK drives launch through `LaunchRevit`/`StartProgram`/`StartArguments`. | | A debug session starts Revit but the add-in is stale | Enable `DeployAddin`; the build deploys before launch. | | Hot Reload does nothing while repacking is on | Disable `IsRepackable` for debug; isolate dependencies via the manifest. | | The wrong Revit year launches | `StartProgram` uses `$(RevitVersion)`; select the matching configuration. |