When running sshuttle in daemon mode with pidfile flag set to a file in a directory, to which current user does not have write permissions, the command silently fails without proper exit code.

Steps to reproduce

1. Create a directory to which only root has write access sudo mkdir directory-for-pidfile
2. Run sshuttle in daemon mode sshuttle --daemon --pidfile="./directory-for-pidfile/pid" --remote <some-remote> <some-cidr>
3. Check output of echo $?
4. Check output of pgrep -f sshuttle

Expected results

Sshuttle does not start and the exit code of the sshuttle command is different than 0.

Actual results

Sshuttle does not start, but the exit code of the sshuttle command is 0.