From ba8d4cc98ff67ef6a6a5e733dffd95a45ea17e87 Mon Sep 17 00:00:00 2001
From: Onur Solmaz <2453968+osolmaz@users.noreply.github.com>
Date: Wed, 8 Apr 2026 19:18:50 +0100
Subject: [PATCH] update: keep global install env pass-through when unchanged

---
 src/infra/update-global.ts | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/infra/update-global.ts b/src/infra/update-global.ts
index 31bee8fb838..dd6debeee39 100644
--- a/src/infra/update-global.ts
+++ b/src/infra/update-global.ts
@@ -171,10 +171,19 @@ export function resolveGlobalInstallSpec(params: {
 
 export async function createGlobalInstallEnv(
   env?: NodeJS.ProcessEnv,
-): Promise<Record<string, string>> {
+): Promise<NodeJS.ProcessEnv | undefined> {
   const pathPrepend = await resolvePortableGitPathPrepend(env);
+  const sourceEnv = env ?? process.env;
+  const hasCorepackDownloadPromptSetting = Boolean(
+    sourceEnv.COREPACK_ENABLE_DOWNLOAD_PROMPT?.trim(),
+  );
+  const requiresMergedEnv =
+    pathPrepend.length > 0 || process.platform === "win32" || !hasCorepackDownloadPromptSetting;
+  if (!requiresMergedEnv) {
+    return env;
+  }
   const merged = Object.fromEntries(
-    Object.entries(env ?? process.env)
+    Object.entries(sourceEnv)
       .filter(([, value]) => value != null)
       .map(([key, value]) => [key, String(value)]),
   ) as Record<string, string>;