How can I debug Dart Builders with breakpoints in WebStorm

Question

Dart uses the build package to generate code. What if you want to debug your own Builder or an existing one?

Answer 1

Instead of calling pub run build_runner you can execute and debug the file build.dart which can be found here:

.dart_tool/build/entrypoint/

To enter your command like serve as in pub run build_runner serve you can edit your debug configurations:

Put the command inside the field Program arguments:

Click Apply and start debugging again. Webstorm will interrupt when a breakpoint is reached.