/usr/bin/varnishlog-json: invalid option -- '-'
Usage: /usr/bin/varnishlog-json <options>

Options:
 [-a]                      Append to file
 [-b]                      Only display backend records
 [-c]                      Only display client records
 [-C]                      Caseless regular expressions
 [-d]                      Process old log entries and exit
 [-D]                      Daemonize
 [-E]                      Display ESI transactions
 [-g <probe|request|vxid>] Grouping mode (default: vxid)
 [-h]                      Usage help
 [-i <taglist>]            Include tags
 [-I <[taglist:]regex>]    Include by regex
 [-k <num>]                Limit transactions
 [-L <limit>]              Incomplete transaction limit
 [-n <workdir>]            varnish working directory
 [-p]                      Pretty-print
 [-P <file>]               PID file
 [-Q <file>]               VSL query file
 [-q <query>]              VSL query
 [-r <filename>]           Binary file input
 [-R <limit[/duration]>]   Output rate limit
 [-t <seconds|off>]        VSM connection timeout
 [-T <seconds>]            Transaction end timeout
 [-V]                      Version
 [-w <filename>]           Output filename
 [-x <taglist>]            Exclude tags
 [-X <[taglist:]regex>]    Exclude by regex