From 82bea58ae3e2563dc4fb3dd526faf706d220e3c1 Mon Sep 17 00:00:00 2001
From: Robin1987China <41602358+Robin1987China@users.noreply.github.com>
Date: Tue, 30 Jun 2026 18:55:21 +0800
Subject: [PATCH] fix(cli): write error message to stderr before showing help

When the user passes an unknown argument or invalid value, the .fail()
handler calls cli.showHelp() but never writes the error message to
stderr.  This makes opencode --unkown-flag silently show help output
identical to opencode --help, leaving the user unaware of the error.

Closes #29390
---
 packages/opencode/src/index.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/opencode/src/index.ts b/packages/opencode/src/index.ts
index 13540a73a36f..43adb5685560 100644
--- a/packages/opencode/src/index.ts
+++ b/packages/opencode/src/index.ts
@@ -108,6 +108,7 @@ const cli = yargs(args)
       msg?.startsWith("Invalid values:")
     ) {
       if (err) throw err
+      if (msg) process.stderr.write(msg + "\n")
       cli.showHelp(show)
     }
     if (err) throw err