Getting stuck at 'Running commands' > Shell > undefined

Application hangs indefinitely at the shell execution stage with an undefined reference.

Environment:

OS: Windows 10
OpenCode Version: 1.0.164
Console: cmder

This issue might be a duplicate of existing issues. Please check:

TUI hangs when shell outputs massive log #4239: TUI hangs when shell outputs massive log
[BUG] OpenCode just hangs randomly after receiving instructions #2940: OpenCode just hangs randomly after receiving instructions
MCP client failing makes opencode hang. #3273: MCP client failing makes opencode hang
Session hangs after file write tool execution with massive latency spike #4061: Session hangs after file write tool execution with massive latency spike

Feel free to ignore if none of these address your specific case.

/oc any idea what could be causing this? look at what shell the packages/desktop uses for the pty ajd figure out what could result in this

Now I have a complete picture. Let me summarize the findings:

Analysis: "Running commands > Shell > undefined" Issue

Root Cause

The issue is not directly related to the PTY shell detection in the desktop package. Instead, this appears to be related to how the bash tool renders in the UI when props.input.description is undefined.

Looking at the UI component in packages/ui/src/components/message-part.tsx lines 426-431:

<BasicTool
  icon="console"
  trigger={{
    title: "Shell",
    subtitle: props.input.description,
  }}
>

The subtitle is set to props.input.description. When the LLM calls the bash tool without providing the description parameter, this value is undefined.

In basic-tool.tsx line 51-60, there's a <Show when={trigger().subtitle}> check that should hide it when falsy. However, if the description is the literal string "undefined" (which can happen during JSON serialization/deserialization), it would still display.

Potential Causes

The model is sending the literal string "undefined" as the description parameter instead of omitting it or sending null.
JSON serialization issue: When tool inputs are serialized/deserialized, undefined values might be converted to the string "undefined".
Windows-specific issue: On Windows with cmder, there may be something unusual about how the environment or tool inputs are being processed.

Shell Detection on Windows

The shell detection in packages/opencode/src/shell/shell.ts is actually robust and should never return undefined:

function fallback() {
  if (process.platform === "win32") {
    if (Flag.OPENCODE_GIT_BASH_PATH) return Flag.OPENCODE_GIT_BASH_PATH
    const git = Bun.which("git")
    if (git) {
      const bash = path.join(git, "..", "..", "bin", "bash.exe")
      if (Bun.file(bash).size) return bash  // ⚠️ Potential issue here
    }
    return process.env.COMSPEC || "cmd.exe"  // Always has fallback
  }
  // ...
}

One edge case: Bun.file(bash).size is async but is being used synchronously. This could return a Promise object that's truthy but not a valid shell path. However, this wouldn't produce the string "undefined".

Recommendation

The issue is most likely that the bash tool's description parameter is being displayed as the literal string "undefined". The fix would be to add defensive handling in the UI:

subtitle: props.input.description || undefined,

This ensures that falsy strings like empty string or the string "undefined" aren't displayed.

opencode session | github run

running with --print-logs, i get these:

ERROR 2025-12-17T02:09:45 +151ms service=acp-command promise={} reason=NotFoundError Unhandled rejection
ERROR 2025-12-17T02:09:45 +1ms service=default e=NotFoundError rejection
INFO 2025-12-17T02:09:46 +461ms service=bus type=session.updated publishing
INFO 2025-12-17T02:09:46 +2ms service=bus type=session.diff publishing
ERROR 2025-12-17T02:09:47 +1013ms service=acp-command promise={} reason=NotFoundError Unhandled rejection
ERROR 2025-12-17T02:09:47 +0ms service=default e=NotFoundError rejection
INFO 2025-12-17T02:09:53 +6233ms service=session.summary title=Checking Current Status title
INFO 2025-12-17T02:09:53 +1ms service=bus type=message.updated publishing
ERROR 2025-12-17T02:09:54 +1005ms service=acp-command promise={} reason=NotFoundError Unhandled rejection
ERROR 2025-12-17T02:09:54 +0ms service=default e=NotFoundError rejection
INFO 2025-12-17T02:10:02 +8317ms service=snapshot hash=3745f8b408349c5a1ab621d58ef9f5f0642b16c1
cwd=C:[project path] git=C:[user path].local\share\opencode\snapshot\c5b6b9820d4608b7746befe7c7b05d559b3e8f05 tracking
INFO 2025-12-17T02:10:02 +3ms service=bus type=message.part.updated publishing
INFO 2025-12-17T02:10:02 +5ms service=bus type=message.part.updated publishing
ERROR 2025-12-17T02:10:03 +1002ms service=acp-command promise={} reason=NotFoundError Unhandled rejection
ERROR 2025-12-17T02:10:03 +0ms service=default e=NotFoundError rejection
INFO 2025-12-17T02:10:04 +978ms service=bus type=message.part.updated publishing
INFO 2025-12-17T02:10:05 +331ms service=bus type=message.part.updated publishing
INFO 2025-12-17T02:10:05 +8ms service=bus type=message.part.updated publishing
INFO 2025-12-17T02:10:05 +29ms service=permission sessionID=ses_4d84b8842ffedJ5Fi5cf25T3wS messageID=msg_b2a120e73002idlMUkP93KoBoH toolCallID=call_d4906847513741d9b6c3011e pattern=["git status *"] asking
INFO 2025-12-17T02:10:05 +1ms service=bus type=permission.updated publishing
ERROR 2025-12-17T02:10:05 +646ms service=acp-command promise={} reason=NotFoundError Unhandled rejection
ERROR 2025-12-17T02:10:05 +1ms service=default e=NotFoundError rejection
INFO 2025-12-17T02:10:05 +7ms service=bus type=message.part.updated publishing
INFO 2025-12-17T02:10:05 +2ms service=bus type=message.part.updated publishing
ERROR 2025-12-17T02:10:06 +1005ms service=acp-command promise={} reason=NotFoundError Unhandled rejection
ERROR 2025-12-17T02:10:06 +1ms service=default e=NotFoundError rejection

hm need to figure out that not found error looks like cause

I took the desktop app for a spin and ran into this error as well. Agent runs shell command that presents undefined then just continues to spin indefinitely.

can u share a session w me?

I'm trying to replicate it, but I think it could be from continuing a session that was first started via cli, then opening it in desktop. Off 1.0.193, running a session from start on desktop, I haven't been able to make it fail.

I'm trying to replicate it, but I think it could be from continuing a session that was first started via cli, then opening it in desktop. Off 1.0.193, running a session from start on desktop, I haven't been able to make it fail.

Spoke too soon. Unfortunately, I can't share this particular session.

I have the same Problem, it was a newly fresh created session in open code.
The problem accrued after the first update today to V1.0.195 (MacOS).
Not my biggest want but it is no big deal for me to share the session with a developer.

@rekram1-node

It is strange, even when I make a new session inside the project the error persists.
Only when I make a new project it behaves normal again.
@rekram1-node how can I send you the Session Link? The Discord Link in your bio is expired.
Or should I send to @adamdotdevin since he is assigned now?

Anyone encountered any kind of work around?

I am kinda stuck with my work, I already got used to OpenCode with in just a day, that I rather wait until it is fixed.
But I can't also wait weeks or indefinitely :P Thanks by the way for all contributors initiators, for every invested second!

To stay organized issues are automatically closed after 90 days of no activity. If the issue is still relevant please open a new one.

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Getting stuck at 'Running commands' > Shell > undefined #5662

Analysis: "Running commands > Shell > undefined" Issue

Root Cause

Potential Causes

Shell Detection on Windows

Recommendation

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Getting stuck at 'Running commands' > Shell > undefined #5662

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github-actions commented on Dec 17, 2025

rekram1-node commented on Dec 17, 2025

opencode-agent commented on Dec 17, 2025

Analysis: "Running commands > Shell > undefined" Issue

Root Cause

Potential Causes

Shell Detection on Windows

Recommendation

badrul commented on Dec 17, 2025

rekram1-node commented on Dec 17, 2025

wolfie82 commented on Dec 23, 2025

rekram1-node commented on Dec 23, 2025

wolfie82 commented on Dec 23, 2025

wolfie82 commented on Dec 23, 2025

aldaw commented on Dec 24, 2025

aldaw commented on Dec 25, 2025

aldaw commented on Dec 25, 2025

github-actions commented on Mar 25, 2026

johnsonsleo commented on Apr 4, 2026

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