tests: Fix the expected error message for Dockerfile syntax errors

.mocharc.js

@@ -1,4 +1,7 @@
 module.exports = {
   timeout: 25000,
   spec: 'test/**/*.spec.ts',
+  // TODO: This shouldn't be necessary, but the tests on node20 hang, while they pass on node 16 & 18.
+  // `leaked-handles` showed an unclosed docker deamon connection.
+  exit: true,
 };

package.json

@@ -62,7 +62,7 @@
     "proxyquire": "^2.1.3",
     "rimraf": "^5.0.1",
     "ts-mocha": "^10.0.0",
-    "typescript": "^5.1.6"
+    "typescript": "~5.1.6"
   },
   "dependencies": {
     "ajv": "^6.12.3",

test/multibuild/build.spec.ts

@@ -521,7 +521,7 @@ describe('Specifying a dockerfile', () => {
 				.to.have.property('error')
 				.that.has.property('message')
 				.that.matches(
-					/Dockerfile parse error line 1: unknown instruction: CORRECT/i,
+					/Dockerfile parse error (on )?line 1: unknown instruction: CORRECT/i,
 				);
 		});
 	});
@@ -554,7 +554,7 @@ describe('Specifying a dockerfile', () => {
 				.to.have.property('error')
 				.that.has.property('message')
 				.that.matches(
-					/Dockerfile parse error line 1: unknown instruction: CORRECT/i,
+					/Dockerfile parse error (on )?line 1: unknown instruction: CORRECT/i,
 				);
 		});
 	});
@@ -601,7 +601,7 @@ describe('Specifying a dockerfile hook', () => {
 				.to.have.property('error')
 				.that.has.property('message')
 				.that.matches(
-					/Dockerfile parse error line 1: unknown instruction: CORRECT/i,
+					/Dockerfile parse error (on )?line 1: unknown instruction: CORRECT/i,
 				);
 		});
 	});