nx-dagger: Wrap parallel map access in mutex

.changeset/quick-squids-cover.md

@@ -0,0 +1,5 @@
+---
+"nx-dagger": patch
+---
+
+Wrap parallel map access in mutex

apps/nx-dagger/src/generate/main.go.eta

@@ -93,6 +93,8 @@ var nxConfig = map[NxProjectDir]NxProject{
 <% } %>
 }
 
+var mapMutex = sync.RWMutex{}
+
 // Execute Nx targets over all projects in dependency order
 // and return the fully built monorepo directory
 func (m *<%= it.changeCase.pascalCase(it.dagger.name) %>) Build(
@@ -132,7 +134,9 @@ func (m *<%= it.changeCase.pascalCase(it.dagger.name) %>) Build(
 			if buildError != nil {
 				return buildError
 			}
+			mapMutex.RLock()
 			dependencyDirs[dependencyProjectDir] = builtProjects[dependencyProjectDir].directory
+			mapMutex.RUnlock()
 		}
 
 		directory, err := m.buildProject(
@@ -152,15 +156,20 @@ func (m *<%= it.changeCase.pascalCase(it.dagger.name) %>) Build(
 				buildError = err
 			}
 		} else {
+			mapMutex.Lock()
+			defer mapMutex.Unlock()
 			project := builtProjects[projectDir]
 			project.directory = directory
 			builtProjects[projectDir] = project
 		}
 		return nil
 	}
 	triggerProjectBuildGroup = func(projectDir NxProjectDir) {
+		mapMutex.RLock()
+		projectOnce := builtProjects[projectDir].once
+		mapMutex.RUnlock()
 		// Only run project build once, reporting wait/error groups
-		builtProjects[projectDir].once.Do(func() {
+		projectOnce.Do(func() {
 			defer waitGroup.Done()
 			triggerProjectBuild(projectDir)
 		})