sipeed/picoclaw · critical

error in open panic: %v

Error message

error in open panic: %v

What it means

Startup panic in the unix build of logger.InitPanic: initPanicFile could not os.OpenFile the panic log (default <picoclaw home>/logs/launcher_panic.log) with O_WRONLY|O_CREATE|O_APPEND|O_SYNC, mode 0600. Because this file is the designated crash-output destination, failure to create it is fatal — the process aborts immediately, before logging is initialized.

Source

Thrown at pkg/logger/panic_unix.go:16

//go:build !windows

package logger

import (
	"fmt"
	"io"
	"os"

	"golang.org/x/sys/unix"
)

func initPanicFile(panicFile string) io.WriteCloser {
	file, err := os.OpenFile(panicFile, os.O_WRONLY|os.O_CREATE|os.O_APPEND|os.O_SYNC, 0o600)
	if err != nil {
		panic(fmt.Sprintf("error in open panic: %v", err))
	}
	if err = unix.Dup2(int(file.Fd()), int(os.Stderr.Fd())); err != nil {
		panic(fmt.Sprintf("error in syscall.Dup2: %v", err))
	}
	return file
}

View on GitHub (pinned to 49183d7e8d)

Solutions

1. Read the %v in the panic text — the errno distinguishes permission denied, read-only file system, and no space left on device
2. Make the logs directory writable by the service user (mkdir -p + chown/chmod)
3. In containers, mount a writable volume at the logs path or point PICO_HOME at a writable directory
4. Free space or raise quota if the errno is ENOSPC

Example fix

# before
PICO_HOME=/opt/picoclaw ./launcher   # not writable by app user

# after
PICO_HOME=/var/lib/picoclaw ./launcher  # writable by app user

dir := filepath.Join(utils.GetPicoclawHome(), "logs")
if err := os.MkdirAll(dir, 0o755); err != nil {
    return fmt.Errorf("log dir %s unusable: %w", dir, err)
}
if err := unix.Access(dir, unix.W_OK); err != nil {
    return fmt.Errorf("log dir %s not writable: %w", dir, err)
}

The panic fires before in-process error handling is usable; catch it at the supervisor level: a fast startup exit with this message is a permissions/config incident — surface the text and fail the deploy.

When it happens

Trigger: The home/logs directory is not writable by the runtime user: permission denied, read-only root filesystem/container, a path component that is a regular file, disk full/quota exceeded, or a directory previously created by root with 0700 now used by an unprivileged user.

Common situations: Containers with read-only FS missing a writable volume mount; first run as a different user after root created the home; PICO_HOME pointing at an invalid path; SELinux/AppArmor denials.

Related errors

• error initializing panic log: %v
• error in syscall.Dup2: %v
• error in open panic: %v
• error enabling file logging: %v
• create session store dir: %w

AI-assisted analysis of sipeed/picoclaw@49183d7e8d (2026-08-15). Data as JSON: /api/errors/776baa20da5aa7f0. Report an issue: GitHub.