probelabs/goreplay · error

open pcap file error: %q

Error message

open pcap file error: %q

What it means

activatePcapFile wraps pcap.OpenOffline's failure to open the capture file given as the input host (missing file, bad permissions, or not a valid pcap/pcapng file), aborting replay from file.

Source

Thrown at internal/capture/capture.go:686

			msg += ("\n" + e.Error())
			continue
		}
		l.Handles[ifi.Name] = packetHandle{
			handler: handle,
			ips:     interfaceIPs(ifi),
		}
	}
	if len(l.Handles) == 0 {
		return fmt.Errorf("raw socket handles error:%s", msg)
	}
	return nil
}

func (l *Listener) activatePcapFile() (err error) {
	var handle *pcap.Handle
	var e error
	if handle, e = pcap.OpenOffline(l.host); e != nil {
		return fmt.Errorf("open pcap file error: %q", e)
	}

	tmp := l.host
	l.host = ""
	l.config.BPFFilter = l.Filter(pcap.Interface{})
	l.host = tmp

	if e = handle.SetBPFFilter(l.config.BPFFilter); e != nil {
		handle.Close()
		return fmt.Errorf("BPF filter error: %q, filter: %s", e, l.config.BPFFilter)
	}

	fmt.Println("BPF Filter:", l.config.BPFFilter)

	l.Handles["pcap_file"] = packetHandle{
		handler: handle,
	}
	return

View on GitHub (pinned to 251e45abd2)

Solutions

1. Check the file path exists and is readable
2. Verify the file is a valid pcap capture produced by gor or tcpdump
3. Confirm correct file extension/format (gzip-compressed files need matching support)

When it happens

Trigger: Thrown at internal/capture/capture.go:686 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of probelabs/goreplay@251e45abd2 (2026-09-02). Data as JSON: /api/errors/ed8dc6979479012d. Report an issue: GitHub.