From ea8811b444dc191fe9666562547c0cb654b3757a Mon Sep 17 00:00:00 2001
From: Steven Silvester <steven.silvester@ieee.org>
Date: Fri, 16 Aug 2019 13:57:37 -0500
Subject: [PATCH] Backport PR #7013: Do not fail on deduplicate and ignore
 optional

---
 buildutils/src/update-core-mode.ts | 2 +-
 jupyterlab/commands.py             | 2 +-
 jupyterlab/staging/.yarnrc         | 1 +
 package.json                       | 2 +-
 4 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/buildutils/src/update-core-mode.ts b/buildutils/src/update-core-mode.ts
index 36429be7708b..99da37a4ab40 100644
--- a/buildutils/src/update-core-mode.ts
+++ b/buildutils/src/update-core-mode.ts
@@ -36,7 +36,7 @@ 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 });
diff --git a/jupyterlab/commands.py b/jupyterlab/commands.py
index d2e2c89c638e..87ec97ff49d3 100644
--- a/jupyterlab/commands.py
+++ b/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
 
diff --git a/jupyterlab/staging/.yarnrc b/jupyterlab/staging/.yarnrc
index b3fd51732629..be4f5194ad3a 100644
--- a/jupyterlab/staging/.yarnrc
+++ b/jupyterlab/staging/.yarnrc
@@ -1 +1,2 @@
 yarn-path "./yarn.js"
+ignore-optional true
diff --git a/package.json b/package.json
index 0790ee3d7fbd..c44c8fc1f98e 100644
--- a/package.json
+++ b/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 .",