diff --git a/europa-universe/docker/build.cue b/europa-universe/docker/build.cue
index c7ec2128..f8d41797 100644
--- a/europa-universe/docker/build.cue
+++ b/europa-universe/docker/build.cue
@@ -13,28 +13,41 @@ import (
 	// Generate build DAG from linerar steps
 	dag: {
 		for idx, step in steps {
-			// As a special case, wrap #Run into a valid step
-			if step.run != _|_ {
-				"\(idx)": {
-					input: _
-					run:   step & {
-						image: input
-						output: rootfs: _
-					}
-					output: {
-						config: input.config
-						rootfs: run.output.rootfs
-					}
-				}
-			}
+			///// FIXME: this section is broken and in the middle of debug + rewrite
+			//// // 1. image -> input
+			//// if (step.input == _|_) && ((step.image & #Image) != _|_) {
+			////  input: image
+			//// }
 
-			// Otherwise, just use the step as is
-			if step.run == _|_ {
-				"\(idx)": {
-					run: false
-					step
-				}
-			}
+			//// // 2. 
+			//// if ((step.output & docker.#Image) == _|_) && ((step.output.rootfs & dagger.#FS) != _|_) {
+			////  
+			//// }
+
+			//// // As a special case, wrap #Run into a valid step
+			//// if step.run != _|_ {
+			////  "\(idx)": {
+			////   input: _
+			////   run:   step & {
+			////    image: input
+			////    output: rootfs: _
+			////   }
+			////   output: {
+			////    config: input.config
+			////    rootfs: run.output.rootfs
+			////   }
+			////  }
+			//// }
+
+			//// // Otherwise, just use the step as is
+			//// if step.run == _|_ {
+			////  "\(idx)": {
+			////   run: false
+			////   step
+			////  }
+			//// }
+
+			"\(idx)": step
 
 			// Either way, connect input to previous output
 			if idx > 0 {
diff --git a/europa-universe/docker/docker.cue b/europa-universe/docker/docker.cue
index 154e6b7c..13d20a35 100644
--- a/europa-universe/docker/docker.cue
+++ b/europa-universe/docker/docker.cue
@@ -19,8 +19,8 @@ import (
 
 // Run a command in a container
 #Run: {
-	run:   true // FIXME
 	image: #Image
+	input: image // for compatibility with #Build
 
 	always: bool | *false
 
@@ -104,7 +104,10 @@ import (
 			message: string | *null
 		}
 
-		output: {
+		output?: {
+			// FIXME: hack for #Build compatibility
+			#Image
+
 			rootfs?: dagger.#FS & _exec.output
 			files: [path=string]: {
 				contents: string
diff --git a/europa-universe/examples/changelog.com/ci.cue b/europa-universe/examples/changelog.com/ci.cue
deleted file mode 100644
index b9053037..00000000
--- a/europa-universe/examples/changelog.com/ci.cue
+++ /dev/null
@@ -1,363 +0,0 @@
-// STARTING POINT: https://docs.dagger.io/1012/ci
-// + ../../../.circleci/config.yml
-package ci
-
-import (
-	"dagger.io/dagger"
-	"universe.dagger.io/docker"
-)
-
-dagger.#Plan & {
-	// Receive things from client
-	input: {
-		directories: {
-			// App source code
-			app: {}
-		}
-		secrets: {
-			// Docker ID password
-			docker: {}
-		}
-		params: {
-			// Which Elixir base image to download
-			runtime_image: docker.#Ref | *"thechangelog/runtime:2021-05-29T10.17.12Z"
-			// Which test DB image to download
-			test_db_image: docker.#Ref | *"circleci/postgres:12.6"
-		}
-	}
-
-	// Send things to client
-	output: {
-	}
-
-	// Forward network services to and from the client
-	proxy: {
-	}
-
-	// Do things
-	actions: {
-	
-		// Reuse in all mix commands
-		_appName: "changelog"
-	
-		prod: {
-
-			assets: docker.#Build & {
-				steps: [
-					// 1. Start from dev assets :)
-					dev.assets,
-					// 2. Mix magical command
-					#mixRun & {
-						script: "mix phx.digest"
-						mix: {
-							env: "prod"
-							app: _appName
-							depsCache: "readonly"
-							buildCache: "readonly"
-						}
-						// FIXME: remove copy-pasta
-						mounts: nodeModules: {
-							contents: engine.#CacheDir & {
-								// FIXME: do we need an ID here?
-								id: "\(mix.app)_assets_node_modules"
-								// FIXME: does this command need write access to node_modules cache?
-								concurrency: "readonly"
-							}
-							dest: "\(workdir)/node_modules"
-						}
-					}
-				]
-			}
-
-		}
-
-		dev: {
-			build: #mixBuild & {
-				"env": "dev"
-				app: "thechangelog"
-				base: input.params.runtime_image
-				source: input.directories.app.contents
-			}
-
-			assets: docker.#Build & {
-				steps: [
-					// 1. Start from dev runtime build
-					build,
-					// 2. Build web assets
-					#mixRun & {
-						mix: {
-							env: "dev"
-							app: _appName
-							depsCache: "readonly"
-							buildCache: "readonly"
-						}
-						// FIXME: move this to a reusable def (yarn package? or private?)
-						mounts: nodeModules: {
-							contents: engine.#CacheDir & {
-								// FIXME: do we need an ID here?
-								id: "\(mix.app)_assets_node_modules"
-								// FIXME: will there be multiple writers?
-								concurrency: "locked"
-							}
-							dest: "\(workdir)/node_modules"
-						}
-						// FIXME: run 'yarn install' and 'yarn run compile' separately, with different caching?
-						// FIXME: can we reuse universe.dagger.io/yarn ???? 0:-)
-						script: "yarn install --frozen-lockfile && yarn run compile"
-						workdir: "/app/assets"
-					}
-				]
-			}
-		}
-		test: {
-	
-			build: #mixBuild & {
-				"env": "test"
-				app: _appName
-				base: input.params.runtime_image
-				source: input.directories.app.contents
-			}
-	
-			// Run tests
-			run: docker.#Run & {
-				image: build.output
-				script: "mix test"
-				// Don't cache running tests
-				// Just because we've tested a version before, doesn't mean we don't
-				// want to test it again.
-				always: true
-			}
-
-			db: {
-				// Pull test DB image
-				pull: docker.#Pull & {
-					source: input.params.test_db_image
-				}
-
-				// Run test DB
-				// FIXME: kill once no longer needed (when tests are done running)
-				run: docker.#Run & {
-					image: pull.output
-				}
-			}
-		}
-	}
-}
-
-
-
-
-
-
-// Helper to run mix correctly in a container
-#mixRun: {
-	mix: {
-		app: string
-		env: string
-		depsCache?: "readonly" | "locked"
-		buildCache?: "readonly" | "locked"
-	}
-	"env": MIX_ENV: env
-	{
-		mix: depsCache: string
-		workdir: string
-		mounts: depsCache: {
-			contents: engine.#CacheDir & {
-				id: "\(mix.app)_deps"
-				concurrency: mix.depsCache
-			}
-			dest: "\(workdir)/deps"
-		}
-	} | {}
-	{
-		mix: buildCache: string
-		workdir: string
-		mounts: buildCache: {
-			contents: engine.#CacheDir & {
-				id: "\(mix.app)_deps"
-				concurrency: mix.buildCache
-			}
-			dest: "\(workdir)/deps"
-		}
-	} | {}
-}
-
-// FIXME: move into an elixir package
-// Build an Elixir application with Mix
-#mixBuild: {
-	// Ref to base image
-	// FIXME: spin out docker.#Build for max flexibility
-	//   Perhaps implement as a custom docker.#Build step?
-	base: docker.#Ref
-
-	// App name (for cache scoping)
-	app: string
-
-	// Mix environment
-	env: string
-
-	// Application source code
-	source: dagger.#FS
-
-	docker.#Build & {
-                steps: [
-                        // 1. Pull base image
-                        docker.#Pull & {
-                                source: base
-                        },
-                        // 2. Copy app source
-                        docker.#Copy & {
-                                contents: source
-                                dest: "/app"
-                        },
-			// 3. Download dependencies into deps cache
-			#mixRun & {
-				mix: {
-					"env": env
-					"app": app
-					depsCache: "locked"
-				}
-				workdir: "/app"
-				script: "mix deps.get"
-			},
-			// 4. Build!
-			#mixRun & {
-				mix: {
-					"env": env
-					"app": app
-					depsCache: "readonly"
-					buildCache: "locked"
-				}
-				workdir: "/app"
-				script: "mix do deps.compile, compile"
-                        },
-			// 5. Set image config
-			// FIXME: how does this actually work? Does it mutate the field? Or is the field somehow
-			// prevented from being concrete? And if so, how?
-			docker.#Set & {
-				workdir: "/app"
-				"env": MIX_ENV: env				
-			}
-                ]
-        }
-}
-
-
-/////////////////
-/////////////////
-/////////////////
-
-app:                dagger.#Artifact
-prod_dockerfile:    string
-docker_host:        string
-dockerhub_username: string
-dockerhub_password: dagger.#Secret
-// Keep this in sync with ../docker/Dockerfile.production
-runtime_image_ref: dagger.#Input & {string | *"thechangelog/runtime:2021-05-29T10.17.12Z"}
-prod_image_ref:    dagger.#Input & {string | *"thechangelog/changelog.com:dagger"}
-build_version:     dagger.#Input & {string}
-git_sha:           dagger.#Input & {string}
-git_author:        dagger.#Input & {string}
-app_version:       dagger.#Input & {string}
-build_url:         dagger.#Input & {string}
-// Keep this in sync with manifests/changelog/db.yml
-test_db_image_ref:      dagger.#Input & {string | *"circleci/postgres:12.6"}
-test_db_container_name: "changelog_test_postgres"
-run_test:               dagger.#Input & {bool}
-
-// STORY #######################################################################
-//
-// 1. Migrate from CircleCI to GitHub Actions
-//    - extract existing build pipeline into Dagger
-//    - run the pipeline locally
-//    - run the pipeline in GitHub Actions
-//
-// 2. Pipeline is up to 9x quicker (40s vs 370s)
-//    - optimistic branching, as pipelines were originally intended
-//    - use our own hardware - Linode g6-dedicated-8
-//    - predictable runs, no queuing
-//    - caching is buildkit layers
-//
-// 3. Open Telemetry integration out-of-the-box
-//    - visualise all steps in Jaeger UI
-
-// CI PIPELINE OVERVIEW ########################################################
-//
-//                  deps_compile_test      deps_compile_dev  /--- deps_compile_prod
-//                  |                      |                 |    |
-//                  v                      v                 |    v
-//                  test_cache             assets_dev        |    image_prod_cache
-//                  |                      |                 |    |
-//                  v                      v                 |    |
-// test_db_start -> test -> test_db_stop   assets_prod <-----/    |
-//                  |                      |                      |
-//                  |                      v                      |
-//                  |                      image_prod <-----------/
-//
-//....................................... TODO .................................
-//                  |                      |
-//                  |                      v
-//                  \--------------------> image_prod_digest
-//
-// ========================== BEFORE | AFTER | CHANGE ===================================
-// Test, build & push           370s |   40s |  9.25x | https://app.circleci.com/pipelines/github/thechangelog/changelog.com/520/workflows/fbb7c701-d25a-42c1-b42c-db514cd770b4
-// + app compile                220s |  150s |  1.46x | https://app.circleci.com/pipelines/github/thechangelog/changelog.com/582/workflows/65500f3d-eccc-49da-9ab0-69846bc812a7
-// + deps compile               480s |  190s |  2.52x | https://app.circleci.com/pipelines/github/thechangelog/changelog.com/532/workflows/94f5a339-52a1-45ba-b39b-1bbb69ed6488
-//
-// Uncached                     ???s |  465s | ?.??x  |
-//
-// #############################################################################
-
-
-
-
-deps_compile_prod: #deps_compile & {
-	args: {
-		MIX_ENV: "prod"
-	}
-}
-
-image_prod_cache: docker.#Build & {
-	source:     deps_compile_prod
-	dockerfile: """
-			FROM \(runtime_image_ref)
-			COPY /app/ /app/
-			WORKDIR /app
-			RUN --mount=type=cache,id=deps,target=/mnt/app/deps,sharing=locked cp -Rp /mnt/app/deps/* /app/deps/
-			RUN --mount=type=cache,id=build_prod,target=/mnt/app/_build/prod,sharing=locked cp -Rp /mnt/app/_build/prod/* /app/_build/prod/
-		"""
-}
-
-image_prod: docker.#Command & {
-	host: docker_host
-	copy: {
-		"/tmp/app": from: os.#Dir & {
-			from: image_prod_cache
-			path: "/app"
-		}
-
-		"/tmp/app/priv/static": from: os.#Dir & {
-			from: assets_prod
-			path: "/app/priv/static"
-		}
-	}
-	env: {
-		GIT_AUTHOR:         git_author
-		GIT_SHA:            git_sha
-		APP_VERSION:        app_version
-		BUILD_VERSION:      build_version
-		BUILD_URL:          build_url
-		DOCKERHUB_USERNAME: dockerhub_username
-		PROD_IMAGE_REF:     prod_image_ref
-	}
-	files: "/tmp/Dockerfile":                  prod_dockerfile
-	secret: "/run/secrets/dockerhub_password": dockerhub_password
-	command: #"""
-		cd /tmp
-		docker build --build-arg GIT_AUTHOR="$GIT_AUTHOR" --build-arg GIT_SHA="$GIT_SHA" --build-arg APP_VERSION="$APP_VERSION" --build-arg BUILD_URL="$BUILD_URL" --tag "$PROD_IMAGE_REF" .
-		docker login --username "$DOCKERHUB_USERNAME" --password "$(cat /run/secrets/dockerhub_password)"
-		docker push "$PROD_IMAGE_REF" | tee docker.push.log
-		echo "$PROD_IMAGE_REF" > image.ref
-		awk '/digest/ { print $3 }' < docker.push.log > image.digest
-		"""#
-}
diff --git a/europa-universe/examples/changelog.com/highlevel/ci.cue b/europa-universe/examples/changelog.com/highlevel/ci.cue
new file mode 100644
index 00000000..57dfae7a
--- /dev/null
+++ b/europa-universe/examples/changelog.com/highlevel/ci.cue
@@ -0,0 +1,134 @@
+package ci
+
+import (
+	"dagger.io/dagger"
+	"dagger.io/dagger/engine"
+
+	"universe.dagger.io/docker"
+	"universe.dagger.io/examples/changelog.com/highlevel/elixir/mix"
+)
+
+dagger.#Plan & {
+	// Receive things from client
+	inputs: {
+		directories: {
+			// App source code
+			app: _
+		}
+		secrets: {
+			// Docker ID password
+			docker: _
+		}
+		params: {
+			// Which Elixir base image to download
+			runtime_image: docker.#Ref | *"thechangelog/runtime:2021-05-29T10.17.12Z"
+			// Which test DB image to download
+			test_db_image: docker.#Ref | *"circleci/postgres:12.6"
+		}
+	}
+
+	// Do things
+	actions: {
+		// Reuse in all mix commands
+		_appName: "changelog"
+
+		prod: assets: docker.#Build & {
+			steps: [
+				// 1. Start from dev assets :)
+				dev.assets,
+				// 2. Mix magical command
+				mix.#Run & {
+					script: "mix phx.digest"
+					mix: {
+						env:        "prod"
+						app:        _appName
+						depsCache:  "readonly"
+						buildCache: "readonly"
+					}
+					workdir: _
+					// FIXME: remove copy-pasta
+					mounts: nodeModules: {
+						contents: engine.#CacheDir & {
+							// FIXME: do we need an ID here?
+							id: "\(mix.app)_assets_node_modules"
+							// FIXME: does this command need write access to node_modules cache?
+							concurrency: "readonly"
+						}
+						dest: "\(workdir)/node_modules"
+					}
+				},
+			]
+		}
+
+		dev: {
+			build: mix.#Build & {
+				env:    "dev"
+				app:    "thechangelog"
+				base:   inputs.params.runtime_image
+				source: inputs.directories.app.contents
+			}
+
+			assets: docker.#Build & {
+				steps: [
+					// 1. Start from dev runtime build
+					build,
+					// 2. Build web assets
+					mix.#Run & {
+						mix: {
+							env:        "dev"
+							app:        _appName
+							depsCache:  "readonly"
+							buildCache: "readonly"
+						}
+						// FIXME: move this to a reusable def (yarn package? or private?)
+						mounts: nodeModules: {
+							contents: engine.#CacheDir & {
+								// FIXME: do we need an ID here?
+								id: "\(mix.app)_assets_node_modules"
+								// FIXME: will there be multiple writers?
+								concurrency: "locked"
+							}
+							dest: "\(workdir)/node_modules"
+						}
+						// FIXME: run 'yarn install' and 'yarn run compile' separately, with different caching?
+						// FIXME: can we reuse universe.dagger.io/yarn ???? 0:-)
+						script:  "yarn install --frozen-lockfile && yarn run compile"
+						workdir: "/app/assets"
+					},
+				]
+			}
+		}
+		test: {
+			build: mix.#Build & {
+				env:    "test"
+				app:    _appName
+				base:   inputs.params.runtime_image
+				source: inputs.directories.app.contents
+			}
+
+			// Run tests
+			run: docker.#Run & {
+				image:  build.output
+				script: "mix test"
+				// Don't cache running tests
+				// Just because we've tested a version before, doesn't mean we don't
+				// want to test it again.
+				// FIXME: make this configurable
+				always: true
+			}
+
+			db: {
+				// Pull test DB image
+				pull: docker.#Pull & {
+					source: inputs.params.test_db_image
+				}
+
+				// Run test DB
+				// FIXME: kill once no longer needed (when tests are done running)
+				run: docker.#Run & {
+					image: pull.output
+				}
+			}
+		}
+	}
+}
diff --git a/europa-universe/examples/changelog.com/highlevel/elixir/mix/mix.cue b/europa-universe/examples/changelog.com/highlevel/elixir/mix/mix.cue
new file mode 100644
index 00000000..ff4c466e
--- /dev/null
+++ b/europa-universe/examples/changelog.com/highlevel/elixir/mix/mix.cue
@@ -0,0 +1,95 @@
+package mix
+
+import (
+	"dagger.io/dagger"
+	"dagger.io/dagger/engine"
+
+	"universe.dagger.io/docker"
+)
+
+// Build an Elixir application with Mix
+#Build: {
+	// Ref to base image
+	// FIXME: spin out docker.#Build for max flexibility
+	//   Perhaps implement as a custom docker.#Build step?
+	base: docker.#Ref
+
+	// App name (for cache scoping)
+	app: string
+
+	// Mix environment
+	env: string
+
+	// Application source code
+	source: dagger.#FS
+
+	docker.#Build & {
+		steps: [
+			// 1. Pull base image
+			docker.#Pull & {
+				source: base
+			},
+			// 2. Copy app source
+			docker.#Copy & {
+				contents: source
+				dest:     "/app"
+			},
+			// 3. Download dependencies into deps cache
+			#Run & {
+				mix: {
+					"env":     env
+					"app":     app
+					depsCache: "locked"
+				}
+				workdir: "/app"
+				script:  "mix deps.get"
+			},
+			// 4. Build!
+			// FIXME: step 5 is to add image data, see issue 1339
+			#Run & {
+				mix: {
+					"env":      env
+					"app":      app
+					depsCache:  "readonly"
+					buildCache: "locked"
+				}
+				workdir: "/app"
+				script:  "mix do deps.compile, compile"
+			},
+		]
+	}
+}
+
+// Run mix correctly in a container
+#Run: {
+	mix: {
+		app:         string
+		env:         string
+		depsCache?:  "readonly" | "locked"
+		buildCache?: "readonly" | "locked"
+	}
+	docker.#Run
+	env: MIX_ENV: mix.env
+	{
+		mix: depsCache: string
+		workdir: string
+		mounts: depsCache: {
+			contents: engine.#CacheDir & {
+				id:          "\(mix.app)_deps"
+				concurrency: mix.depsCache
+			}
+			dest: "\(workdir)/deps"
+		}
+	} | {}
+	{
+		mix: buildCache: string
+		workdir: string
+		mounts: buildCache: {
+			contents: engine.#CacheDir & {
+				id:          "\(mix.app)_deps"
+				concurrency: mix.buildCache
+			}
+			dest: "\(workdir)/deps"
+		}
+	} | {}
+}
diff --git a/europa-universe/examples/changelog.com/highlevel/old.cue b/europa-universe/examples/changelog.com/highlevel/old.cue
new file mode 100644
index 00000000..d70b4dae
--- /dev/null
+++ b/europa-universe/examples/changelog.com/highlevel/old.cue
@@ -0,0 +1,116 @@
+package ci
+
+//  app:                dagger.#Artifact
+//  prod_dockerfile:    string
+//  docker_host:        string
+//  dockerhub_username: string
+//  dockerhub_password: dagger.#Secret
+//  // Keep this in sync with ../docker/Dockerfile.production
+//  runtime_image_ref: dagger.#Input & {string | *"thechangelog/runtime:2021-05-29T10.17.12Z"}
+//  prod_image_ref:    dagger.#Input & {string | *"thechangelog/changelog.com:dagger"}
+//  build_version:     dagger.#Input & {string}
+//  git_sha:           dagger.#Input & {string}
+//  git_author:        dagger.#Input & {string}
+//  app_version:       dagger.#Input & {string}
+//  build_url:         dagger.#Input & {string}
+//  // Keep this in sync with manifests/changelog/db.yml
+//  test_db_image_ref:      dagger.#Input & {string | *"circleci/postgres:12.6"}
+//  test_db_container_name: "changelog_test_postgres"
+//  run_test:               dagger.#Input & {bool}
+//  
+//  // STORY #######################################################################
+//  //
+//  // 1. Migrate from CircleCI to GitHub Actions
+//  //    - extract existing build pipeline into Dagger
+//  //    - run the pipeline locally
+//  //    - run the pipeline in GitHub Actions
+//  //
+//  // 2. Pipeline is up to 9x quicker (40s vs 370s)
+//  //    - optimistic branching, as pipelines were originally intended
+//  //    - use our own hardware - Linode g6-dedicated-8
+//  //    - predictable runs, no queuing
+//  //    - caching is buildkit layers
+//  //
+//  // 3. Open Telemetry integration out-of-the-box
+//  //    - visualise all steps in Jaeger UI
+//  
+//  // CI PIPELINE OVERVIEW ########################################################
+//  //
+//  //                  deps_compile_test      deps_compile_dev  /--- deps_compile_prod
+//  //                  |                      |                 |    |
+//  //                  v                      v                 |    v
+//  //                  test_cache             assets_dev        |    image_prod_cache
+//  //                  |                      |                 |    |
+//  //                  v                      v                 |    |
+//  // test_db_start -> test -> test_db_stop   assets_prod <-----/    |
+//  //                  |                      |                      |
+//  //                  |                      v                      |
+//  //                  |                      image_prod <-----------/
+//  //
+//  //....................................... TODO .................................
+//  //                  |                      |
+//  //                  |                      v
+//  //                  \--------------------> image_prod_digest
+//  //
+//  // ========================== BEFORE | AFTER | CHANGE ===================================
+//  // Test, build & push           370s |   40s |  9.25x | https://app.circleci.com/pipelines/github/thechangelog/changelog.com/520/workflows/fbb7c701-d25a-42c1-b42c-db514cd770b4
+//  // + app compile                220s |  150s |  1.46x | https://app.circleci.com/pipelines/github/thechangelog/changelog.com/582/workflows/65500f3d-eccc-49da-9ab0-69846bc812a7
+//  // + deps compile               480s |  190s |  2.52x | https://app.circleci.com/pipelines/github/thechangelog/changelog.com/532/workflows/94f5a339-52a1-45ba-b39b-1bbb69ed6488
+//  //
+//  // Uncached                     ???s |  465s | ?.??x  |
+//  //
+//  // #############################################################################
+//  
+//  
+//  
+//  
+//  deps_compile_prod: #deps_compile & {
+//   args: {
+//    MIX_ENV: "prod"
+//   }
+//  }
+//  
+//  image_prod_cache: docker.#Build & {
+//   source:     deps_compile_prod
+//   dockerfile: """
+//     FROM \(runtime_image_ref)
+//     COPY /app/ /app/
+//     WORKDIR /app
+//     RUN --mount=type=cache,id=deps,target=/mnt/app/deps,sharing=locked cp -Rp /mnt/app/deps/* /app/deps/
+//     RUN --mount=type=cache,id=build_prod,target=/mnt/app/_build/prod,sharing=locked cp -Rp /mnt/app/_build/prod/* /app/_build/prod/
+//    """
+//  }
+//  
+//  image_prod: docker.#Command & {
+//   host: docker_host
+//   copy: {
+//    "/tmp/app": from: os.#Dir & {
+//     from: image_prod_cache
+//     path: "/app"
+//    }
+//  
+//    "/tmp/app/priv/static": from: os.#Dir & {
+//     from: assets_prod
+//     path: "/app/priv/static"
+//    }
+//   }
+//   env: {
+//    GIT_AUTHOR:         git_author
+//    GIT_SHA:            git_sha
+//    APP_VERSION:        app_version
+//    BUILD_VERSION:      build_version
+//    BUILD_URL:          build_url
+//    DOCKERHUB_USERNAME: dockerhub_username
+//    PROD_IMAGE_REF:     prod_image_ref
+//   }
+//   files: "/tmp/Dockerfile":                  prod_dockerfile
+//   secret: "/run/secrets/dockerhub_password": dockerhub_password
+//   command: #"""
+//    cd /tmp
+//    docker build --build-arg GIT_AUTHOR="$GIT_AUTHOR" --build-arg GIT_SHA="$GIT_SHA" --build-arg APP_VERSION="$APP_VERSION" --build-arg BUILD_URL="$BUILD_URL" --tag "$PROD_IMAGE_REF" .
+//    docker login --username "$DOCKERHUB_USERNAME" --password "$(cat /run/secrets/dockerhub_password)"
+//    docker push "$PROD_IMAGE_REF" | tee docker.push.log
+//    echo "$PROD_IMAGE_REF" > image.ref
+//    awk '/digest/ { print $3 }' < docker.push.log > image.digest
+//    """#
+//  }
diff --git a/europa-universe/examples/changelog.com/lowlevel/README.md b/europa-universe/examples/changelog.com/lowlevel/README.md
new file mode 100644
index 00000000..02912018
--- /dev/null
+++ b/europa-universe/examples/changelog.com/lowlevel/README.md
@@ -0,0 +1,2 @@
+Joel's low-level implementation goes here :)
+
diff --git a/europa-universe/examples/todoapp/base.cue b/europa-universe/examples/todoapp/base.cue
index bb89f149..1c3930c3 100644
--- a/europa-universe/examples/todoapp/base.cue
+++ b/europa-universe/examples/todoapp/base.cue
@@ -22,7 +22,7 @@ dagger.#DAG & {
 				remote: "https://github.com/mdn/todo-react"
 				ref:    "master"
 			}
-			build: source: pull.checkout
+			build: source: pull.output
 		}
 	}
 }
diff --git a/europa-universe/git/git.cue b/europa-universe/git/git.cue
index 9130b676..d8e01f1f 100644
--- a/europa-universe/git/git.cue
+++ b/europa-universe/git/git.cue
@@ -1,8 +1,8 @@
 package git
 
 import (
-	"dagger.io/dagger"
+	"dagger.io/dagger/engine"
 )
 
-#Pull: dagger.#GitPull
-#Push: dagger.#GitPush
+#Pull: engine.#GitPull
+#Push: engine.#GitPush