argoproj/argo-workflows · error

failed to open remote thread in target process %d: %w

Error message

failed to open remote thread in target process %d: %w

What it means

After resolving CtrlRoutine, signalProcess injects a thread into the target process with createRemoteThread(hProc, ..., procCtrlRoutine.Addr(), signal, ...) to emulate a console signal (e.g. CTRL_BREAK) on Windows. If thread creation in the remote process fails, the signal could not be delivered and this wrapped error is returned.

Source

Thrown at workflow/executor/osspecific/signal_windows.go:81

// Code +/- copied from: https://github.com/microsoft/hcsshim/blob/1d69a9c658655b77dd4e5275bff99caad6b38416/internal/jobcontainers/process.go#L251
// License: MIT
// Author: Microsoft
func signalProcess(pid uint32, signal int) error {
	hProc, err := windows.OpenProcess(windows.PROCESS_TERMINATE, true, pid)
	if err != nil {
		return fmt.Errorf("failed to open process: %w", err)
	}
	defer func() {
		_ = windows.Close(hProc)
	}()

	if err := procCtrlRoutine.Find(); err != nil {
		return fmt.Errorf("failed to load CtrlRoutine: %w", err)
	}

	threadHandle, err := createRemoteThread(hProc, nil, 0, procCtrlRoutine.Addr(), uintptr(signal), 0, nil)
	if err != nil {
		return fmt.Errorf("failed to open remote thread in target process %d: %w", pid, err)
	}
	defer func() {
		_ = windows.Close(windows.Handle(threadHandle))
	}()
	return nil
}

// Following code has been generated using github.com/Microsoft/go-winio/tools/mkwinsyscall and inlined
// for easier usage

// HANDLE CreateRemoteThread(
//
//	HANDLE                 hProcess,
//	LPSECURITY_ATTRIBUTES  lpThreadAttributes,
//	SIZE_T                 dwStackSize,
//	LPTHREAD_START_ROUTINE lpStartAddress,
//	LPVOID                 lpParameter,
//	DWORD                  dwCreationFlags,

View on GitHub (pinned to 35bff19146)

Solutions

1. Check the wrapped Windows error: ERROR_ACCESS_DENIED → privileges; ERROR_NOT_ENOUGH_MEMORY/quota → target resource limits
2. If the process is already exiting, treat the signal failure as benign and verify completion via the exit-code file instead
3. Run argoexec with sufficient token privileges for cross-process thread creation in job containers
4. Fall back to TerminateProcess-style hard kill if graceful signaling is not required

// ensure handle allows thread creation
h, err := windows.OpenProcess(windows.PROCESS_TERMINATE|windows.PROCESS_CREATE_THREAD|windows.PROCESS_QUERY_INFORMATION, true, pid)
if err != nil { return err }
windows.Close(h)

if err := osspecific.Kill(pid); err != nil && strings.Contains(err.Error(), "remote thread") {
    // graceful signal failed; fall back to TerminateProcess or accept process-exiting race
}

When it happens

Trigger: Kill() → signalProcess() where createRemoteThread fails on a valid process handle — handle lacks THREAD_CREATE rights, the target process is exiting, or address space/quota restrictions apply.

Common situations: Target process terminating concurrently so remote thread creation is rejected; container/job-object security descriptors blocking thread injection; resource exhaustion (max threads/handles) in the target.

Related errors

• failed to open process: %w
• failed to load CtrlRoutine: %w
• cannot convert stdin to os.File, it was %T
• failed to read container args file %s: %w
• failed to unmarshal container args: %w

AI-assisted analysis of argoproj/argo-workflows@35bff19146 (2026-09-03). Data as JSON: /api/errors/06d930a63d005621. Report an issue: GitHub.