From 17f8594614a74af1af12252e854b60f132dd252e Mon Sep 17 00:00:00 2001
From: David Michon <dmichon-msft@users.noreply.github.com>
Date: Thu, 28 Aug 2025 20:49:03 +0000
Subject: [PATCH] [rush] Optimize detecting local projects when collating
 versions

---
 .../rush/optimize-detect-local_2025-08-28-20-48.json   | 10 ++++++++++
 libraries/rush-lib/src/logic/DependencyAnalyzer.ts     |  5 +++++
 2 files changed, 15 insertions(+)
 create mode 100644 common/changes/@microsoft/rush/optimize-detect-local_2025-08-28-20-48.json

diff --git a/common/changes/@microsoft/rush/optimize-detect-local_2025-08-28-20-48.json b/common/changes/@microsoft/rush/optimize-detect-local_2025-08-28-20-48.json
new file mode 100644
index 00000000000..9ff88261350
--- /dev/null
+++ b/common/changes/@microsoft/rush/optimize-detect-local_2025-08-28-20-48.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush",
+      "comment": "Optimize detection of local projects when collecting implicit preferred versions.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush"
+}
\ No newline at end of file
diff --git a/libraries/rush-lib/src/logic/DependencyAnalyzer.ts b/libraries/rush-lib/src/logic/DependencyAnalyzer.ts
index 531cd46b69f..c8492903b19 100644
--- a/libraries/rush-lib/src/logic/DependencyAnalyzer.ts
+++ b/libraries/rush-lib/src/logic/DependencyAnalyzer.ts
@@ -121,6 +121,11 @@ export class DependencyAnalyzer {
           continue;
         }
 
+        if (dependencyVersion.startsWith('workspace:')) {
+          // If this is a workspace protocol dependency, ignore it.
+          continue;
+        }
+
         // Is it a local project?
         const localProject: RushConfigurationProject | undefined =
           this._rushConfiguration.getProjectByName(dependencyName);