/Users/runner/work/sketcher/sketcher/./.github/actions/build-external/action.yml: (Line: 43, Col: 5, Idx: 1317) - (Line: 43, Col: 5, Idx: 1317): While parsing a block collection, did not find expected '-' indicator.

System.ArgumentException: Unexpected type '' encountered while reading 'action manifest root'. The type 'MappingToken' was expected. at GitHub.DistributedTask.ObjectTemplating.Tokens.TemplateTokenExtensions.AssertMapping(TemplateToken value, String objectDescription) at GitHub.Runner.Worker.ActionManifestManager.Load(IExecutionContext executionContext, String manifestFile)