func isBoringMountFusefsError(err error) bool {
	if err, ok := err.(*exec.ExitError); ok && err.Exited() {
		if status, ok := err.Sys().(syscall.WaitStatus); ok && status.ExitStatus() == 1 {
			return true
		}
	}
	return false
}
isBoringMountFusefsError returns whether the Wait error is
uninteresting; exit status 1 is.
package fuse
import (
	"fmt"
	"log"
	"os"
	"os/exec"
	"strings"
	"sync"
	"syscall"
)
func handleMountFusefsStderr(errCh chan<- error) func(line string) (ignore bool) {
	return func(line string) (ignore bool) {
		const (
			noMountpointPrefix = `mount_fusefs: `
			noMountpointSuffix = `: No such file or directory`
		)
		if strings.HasPrefix(line, noMountpointPrefix) && strings.HasSuffix(line, noMountpointSuffix) {
			mountpoint := line[len(noMountpointPrefix) : len(line)-len(noMountpointSuffix)]
			err := &MountpointDoesNotExistError{
				Path: mountpoint,
			}
			select {
			case errCh <- err:
				return true
			default:
				return false
			}
		}
		return false
	}
}