# Step 11: Build Affected Projects ## Build Affected Apps **Once again make a change to `todos.component.html`:** ```html ``` **Run `npm run affected:build -- --base=master`** Nx will rebuild `todos` app. Why didn't it rebuild `ui`? By default, Nx build libraries in the context of some application. You can change it if you mark a library as `publishable`. ## Affected:\* You can run any target against the affected projects in the graph like this: ```bash npm run affected -- --target=build --base=master ``` !!!!! Run "npm run affected -- --target=invalid --base=master". What do you see? !!!!! No projects to run invalid An error message saying that the "invalid" target is invalid