Do not fail on deduplicate and ignore optional

buildutils/src/update-core-mode.ts

@@ -39,7 +39,7 @@ utils.writePackageData(path.join(staging, 'package.json'), data);
 fs.removeSync(path.join(staging, 'yarn.lock'));
 utils.run('jlpm', { cwd: staging });
 try {
-  utils.run('jlpm yarn-deduplicate -s fewer --fail', { cwd: staging });
+  utils.run('jlpm yarn-deduplicate -s fewer', { cwd: staging });
 } catch {
   // re-run install if we deduped packages!
   utils.run('jlpm', { cwd: staging });

jupyterlab/commands.py

@@ -163,7 +163,7 @@ def dedupe_yarn(path, logger=None):
         pins above, for example, known-bad versions
     """
     had_dupes = ProgressProcess(
-        ['node', YARN_PATH, 'yarn-deduplicate', '-s', 'fewer', '--fail'],
+        ['node', YARN_PATH, 'yarn-deduplicate', '-s', 'fewer'],
         cwd=path, logger=logger
     ).wait() != 0
 

jupyterlab/staging/.yarnrc

@@ -1 +1,2 @@
 yarn-path "./yarn.js"
+ignore-optional true

package.json

@@ -50,7 +50,7 @@
     "create:package": "node buildutils/lib/create-package.js",
     "create:test": "node buildutils/lib/create-test-package.js",
     "create:theme": "node buildutils/lib/create-theme.js",
-    "deduplicate": "jlpm yarn-deduplicate -s fewer --fail",
+    "deduplicate": "jlpm yarn-deduplicate -s fewer",
     "docs": "lerna run docs",
     "eslint": "eslint --fix .",
     "eslint:check": "eslint .",