diff --git a/.travis.yml b/.travis.yml
index 49e19c66b1..82ade2b270 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,8 +14,13 @@ before_script:
 
 script:
   - set -eo pipefail
+  # Building the Docker image
   - docker build --pull --build-arg BUILD_TIMESTAMP=$(date -u +'%Y-%m-%dT%H:%M:%SZ') --build-arg COMMIT_ID="${TRAVIS_COMMIT}" -t "jsii/superchain:nightly" ./superchain
+  # Building jsii itself within the Docker image
   - docker run --rm -it --net=host -v ${PWD}:${PWD} -w ${PWD} jsii/superchain:nightly ./build.sh
+  # Make sure the build did not change the source tree (git diff-index will return non-zero if that's the case)
+  - git diff-index --exit-code --ignore-space-at-eol --stat HEAD
+  # Publish the image to DockerHub when relevant
   - echo "TRAVIS_PULL_REQUEST = ${TRAVIS_PULL_REQUEST:-}"
   - echo "TRAVIS_TAG          = ${TRAVIS_TAG:-}"
   - echo "TRAVIS_BRANCH       = ${TRAVIS_BRANCH:-}"
diff --git a/buildspec.yaml b/buildspec.yaml
index b23384f617..d81ffb028d 100644
--- a/buildspec.yaml
+++ b/buildspec.yaml
@@ -13,6 +13,7 @@ phases:
   post_build:
     commands:
       - "[ -f .BUILD_COMPLETED ] && /bin/bash ./pack.sh"
+      - git diff-index --exit-code --ignore-space-at-eol --stat HEAD
 artifacts:
   files:
     - "**/*"
diff --git a/packages/jsii-diff/package-lock.json b/packages/jsii-diff/package-lock.json
index f3de121af9..50e100aee1 100644
--- a/packages/jsii-diff/package-lock.json
+++ b/packages/jsii-diff/package-lock.json
@@ -1059,40 +1059,6 @@
 			"dev": true,
 			"requires": {
 				"fs-extra": "^8.1.0"
-			},
-			"dependencies": {
-				"fs-extra": {
-					"version": "8.1.0",
-					"resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
-					"integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.2.0",
-						"jsonfile": "^4.0.0",
-						"universalify": "^0.1.0"
-					}
-				},
-				"graceful-fs": {
-					"version": "4.2.0",
-					"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.0.tgz",
-					"integrity": "sha512-jpSvDPV4Cq/bgtpndIWbI5hmYxhQGHPC4d4cqBPb4DLniCfhJokdXhwhaDuLBGLQdvvRum/UiX6ECVIPvDXqdg==",
-					"dev": true
-				},
-				"jsonfile": {
-					"version": "4.0.0",
-					"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
-					"integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.1.6"
-					}
-				},
-				"universalify": {
-					"version": "0.1.2",
-					"resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-					"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
-					"dev": true
-				}
 			}
 		},
 		"jsii-reflect": {
diff --git a/packages/jsii-pacmak/package-lock.json b/packages/jsii-pacmak/package-lock.json
index 2c7c91ee53..62fb820340 100644
--- a/packages/jsii-pacmak/package-lock.json
+++ b/packages/jsii-pacmak/package-lock.json
@@ -116,21 +116,6 @@
 			"dev": true,
 			"requires": {
 				"@scope/jsii-calc-base": "file:../jsii-calc-base"
-			},
-			"dependencies": {
-				"@scope/jsii-calc-base": {
-					"version": "file:../jsii-calc-base",
-					"dev": true,
-					"requires": {
-						"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base"
-					},
-					"dependencies": {
-						"@scope/jsii-calc-base-of-base": {
-							"version": "file:../jsii-calc-base-of-base",
-							"dev": true
-						}
-					}
-				}
 			}
 		},
 		"@types/clone": {
@@ -1057,40 +1042,6 @@
 			"dev": true,
 			"requires": {
 				"fs-extra": "^8.1.0"
-			},
-			"dependencies": {
-				"fs-extra": {
-					"version": "8.1.0",
-					"resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
-					"integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.2.0",
-						"jsonfile": "^4.0.0",
-						"universalify": "^0.1.0"
-					}
-				},
-				"graceful-fs": {
-					"version": "4.2.0",
-					"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.0.tgz",
-					"integrity": "sha512-jpSvDPV4Cq/bgtpndIWbI5hmYxhQGHPC4d4cqBPb4DLniCfhJokdXhwhaDuLBGLQdvvRum/UiX6ECVIPvDXqdg==",
-					"dev": true
-				},
-				"jsonfile": {
-					"version": "4.0.0",
-					"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
-					"integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.1.6"
-					}
-				},
-				"universalify": {
-					"version": "0.1.2",
-					"resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-					"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
-					"dev": true
-				}
 			}
 		},
 		"jsii-calc": {
@@ -1101,51 +1052,6 @@
 				"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base",
 				"@scope/jsii-calc-lib": "file:../jsii-calc-lib",
 				"jsii-calc-bundled": "file:../jsii-calc-bundled"
-			},
-			"dependencies": {
-				"@scope/jsii-calc-base": {
-					"version": "file:../jsii-calc-base",
-					"dev": true,
-					"requires": {
-						"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base"
-					},
-					"dependencies": {
-						"@scope/jsii-calc-base-of-base": {
-							"version": "file:../jsii-calc-base-of-base",
-							"dev": true
-						}
-					}
-				},
-				"@scope/jsii-calc-base-of-base": {
-					"version": "file:../jsii-calc-base-of-base",
-					"dev": true
-				},
-				"@scope/jsii-calc-lib": {
-					"version": "file:../jsii-calc-lib",
-					"dev": true,
-					"requires": {
-						"@scope/jsii-calc-base": "file:../jsii-calc-base"
-					},
-					"dependencies": {
-						"@scope/jsii-calc-base": {
-							"version": "file:../jsii-calc-base",
-							"dev": true,
-							"requires": {
-								"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base"
-							},
-							"dependencies": {
-								"@scope/jsii-calc-base-of-base": {
-									"version": "file:../jsii-calc-base-of-base",
-									"dev": true
-								}
-							}
-						}
-					}
-				},
-				"jsii-calc-bundled": {
-					"version": "file:../jsii-calc-bundled",
-					"dev": true
-				}
 			}
 		},
 		"jsii-dotnet-jsonmodel": {
@@ -1157,12 +1063,6 @@
 			"dev": true,
 			"requires": {
 				"jsii-dotnet-jsonmodel": "file:../jsii-dotnet-jsonmodel"
-			},
-			"dependencies": {
-				"jsii-dotnet-jsonmodel": {
-					"version": "file:../jsii-dotnet-jsonmodel",
-					"dev": true
-				}
 			}
 		},
 		"jsii-java-runtime": {
diff --git a/packages/jsii-reflect/package-lock.json b/packages/jsii-reflect/package-lock.json
index 3c558c1a2f..20985f7e72 100644
--- a/packages/jsii-reflect/package-lock.json
+++ b/packages/jsii-reflect/package-lock.json
@@ -396,21 +396,6 @@
 			"dev": true,
 			"requires": {
 				"@scope/jsii-calc-base": "file:../jsii-calc-base"
-			},
-			"dependencies": {
-				"@scope/jsii-calc-base": {
-					"version": "file:../jsii-calc-base",
-					"dev": true,
-					"requires": {
-						"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base"
-					},
-					"dependencies": {
-						"@scope/jsii-calc-base-of-base": {
-							"version": "file:../jsii-calc-base-of-base",
-							"dev": true
-						}
-					}
-				}
 			}
 		},
 		"@types/babel__core": {
@@ -3558,40 +3543,6 @@
 			"dev": true,
 			"requires": {
 				"fs-extra": "^8.1.0"
-			},
-			"dependencies": {
-				"fs-extra": {
-					"version": "8.1.0",
-					"resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
-					"integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.2.0",
-						"jsonfile": "^4.0.0",
-						"universalify": "^0.1.0"
-					}
-				},
-				"graceful-fs": {
-					"version": "4.2.0",
-					"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.0.tgz",
-					"integrity": "sha512-jpSvDPV4Cq/bgtpndIWbI5hmYxhQGHPC4d4cqBPb4DLniCfhJokdXhwhaDuLBGLQdvvRum/UiX6ECVIPvDXqdg==",
-					"dev": true
-				},
-				"jsonfile": {
-					"version": "4.0.0",
-					"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
-					"integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.1.6"
-					}
-				},
-				"universalify": {
-					"version": "0.1.2",
-					"resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-					"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
-					"dev": true
-				}
 			}
 		},
 		"jsii-calc": {
@@ -3602,51 +3553,6 @@
 				"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base",
 				"@scope/jsii-calc-lib": "file:../jsii-calc-lib",
 				"jsii-calc-bundled": "file:../jsii-calc-bundled"
-			},
-			"dependencies": {
-				"@scope/jsii-calc-base": {
-					"version": "file:../jsii-calc-base",
-					"dev": true,
-					"requires": {
-						"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base"
-					},
-					"dependencies": {
-						"@scope/jsii-calc-base-of-base": {
-							"version": "file:../jsii-calc-base-of-base",
-							"dev": true
-						}
-					}
-				},
-				"@scope/jsii-calc-base-of-base": {
-					"version": "file:../jsii-calc-base-of-base",
-					"dev": true
-				},
-				"@scope/jsii-calc-lib": {
-					"version": "file:../jsii-calc-lib",
-					"dev": true,
-					"requires": {
-						"@scope/jsii-calc-base": "file:../jsii-calc-base"
-					},
-					"dependencies": {
-						"@scope/jsii-calc-base": {
-							"version": "file:../jsii-calc-base",
-							"dev": true,
-							"requires": {
-								"@scope/jsii-calc-base-of-base": "file:../jsii-calc-base-of-base"
-							},
-							"dependencies": {
-								"@scope/jsii-calc-base-of-base": {
-									"version": "file:../jsii-calc-base-of-base",
-									"dev": true
-								}
-							}
-						}
-					}
-				},
-				"jsii-calc-bundled": {
-					"version": "file:../jsii-calc-bundled",
-					"dev": true
-				}
 			}
 		},
 		"jsii-spec": {
diff --git a/packages/jsii/package-lock.json b/packages/jsii/package-lock.json
index f7d9a64af6..45c9cc851a 100644
--- a/packages/jsii/package-lock.json
+++ b/packages/jsii/package-lock.json
@@ -1033,40 +1033,6 @@
 			"dev": true,
 			"requires": {
 				"fs-extra": "^8.1.0"
-			},
-			"dependencies": {
-				"fs-extra": {
-					"version": "8.1.0",
-					"resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
-					"integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.2.0",
-						"jsonfile": "^4.0.0",
-						"universalify": "^0.1.0"
-					}
-				},
-				"graceful-fs": {
-					"version": "4.2.0",
-					"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.0.tgz",
-					"integrity": "sha512-jpSvDPV4Cq/bgtpndIWbI5hmYxhQGHPC4d4cqBPb4DLniCfhJokdXhwhaDuLBGLQdvvRum/UiX6ECVIPvDXqdg==",
-					"dev": true
-				},
-				"jsonfile": {
-					"version": "4.0.0",
-					"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
-					"integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.1.6"
-					}
-				},
-				"universalify": {
-					"version": "0.1.2",
-					"resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-					"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
-					"dev": true
-				}
 			}
 		},
 		"jsii-spec": {
diff --git a/packages/oo-ascii-tree/package-lock.json b/packages/oo-ascii-tree/package-lock.json
index 86ddc5baef..55ef5cf8c5 100644
--- a/packages/oo-ascii-tree/package-lock.json
+++ b/packages/oo-ascii-tree/package-lock.json
@@ -3114,40 +3114,6 @@
 			"dev": true,
 			"requires": {
 				"fs-extra": "^8.1.0"
-			},
-			"dependencies": {
-				"fs-extra": {
-					"version": "8.1.0",
-					"resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
-					"integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.2.0",
-						"jsonfile": "^4.0.0",
-						"universalify": "^0.1.0"
-					}
-				},
-				"graceful-fs": {
-					"version": "4.2.0",
-					"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.0.tgz",
-					"integrity": "sha512-jpSvDPV4Cq/bgtpndIWbI5hmYxhQGHPC4d4cqBPb4DLniCfhJokdXhwhaDuLBGLQdvvRum/UiX6ECVIPvDXqdg==",
-					"dev": true
-				},
-				"jsonfile": {
-					"version": "4.0.0",
-					"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
-					"integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
-					"dev": true,
-					"requires": {
-						"graceful-fs": "^4.1.6"
-					}
-				},
-				"universalify": {
-					"version": "0.1.2",
-					"resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-					"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
-					"dev": true
-				}
 			}
 		},
 		"json-parse-better-errors": {