From bd23808adfdbd7f0fe693b8f0d3afd59ee214e81 Mon Sep 17 00:00:00 2001
From: Luke Parker <10430890+Hona@users.noreply.github.com>
Date: Tue, 13 Oct 2026 11:01:49 +1000
Subject: [PATCH] fix(tui): report x64 emulation on Windows ARM64 (#54984)

---
 packages/core/src/plugin/skill.ts | 5 ++++-
 packages/tui/src/util/system.ts   | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/plugin/skill.ts b/packages/core/src/plugin/skill.ts
index 19422427227..dc2f72cc05e 100644
--- a/packages/core/src/plugin/skill.ts
+++ b/packages/core/src/plugin/skill.ts
@@ -51,6 +51,9 @@ const reportContentWithDiagnostics = Effect.fn("SkillPlugin.reportContentWithDia
   app: Context["app"],
 ) {
   const plugins = yield* configuredPlugins()
+  // Under emulation on Windows ARM64, os.arch() reads x64 but PROCESSOR_IDENTIFIER still names the ARM host.
+  const emulated =
+    process.platform === "win32" && os.arch() === "x64" && process.env.PROCESSOR_IDENTIFIER?.startsWith("ARM")
   return [
     ReportContent,
     "",
@@ -60,7 +63,7 @@ const reportContentWithDiagnostics = Effect.fn("SkillPlugin.reportContentWithDia
     "",
     `- opencode version: ${app.version}`,
     `- install/channel: ${app.channel}`,
-    `- OS: ${os.type()} ${os.release()} (${os.platform()} ${os.arch()})`,
+    `- OS: ${os.type()} ${os.release()} (${os.platform()} ${os.arch()}${emulated ? ", emulated on ARM64" : ""})`,
     `- Terminal: ${terminal()}`,
     `- Shell: ${shell()}`,
     `- Active plugins: ${plugins.length === 0 ? "None found in config" : plugins.join(", ")}`,
diff --git a/packages/tui/src/util/system.ts b/packages/tui/src/util/system.ts
index f55848bfc12..33e15c2fbbb 100644
--- a/packages/tui/src/util/system.ts
+++ b/packages/tui/src/util/system.ts
@@ -9,7 +9,10 @@ export function describeOS() {
         : process.platform === "linux"
           ? "Linux"
           : process.platform
-  return `${name} ${release()} (${process.arch})`
+  // Under emulation on Windows ARM64, process.arch reads x64 but PROCESSOR_IDENTIFIER still names the ARM host.
+  const emulated =
+    process.platform === "win32" && process.arch === "x64" && process.env.PROCESSOR_IDENTIFIER?.startsWith("ARM")
+  return `${name} ${release()} (${process.arch}${emulated ? ", emulated on ARM64" : ""})`
 }
 
 export function describeTerminal() {