ERROR: must give filename

Jsonnet reformatter v0.21.0-rc1

jsonnetfmt {<option>} { <filename> }

Available options:
  -h / --help                This message
  -e / --exec                Treat filename as code
  -o / --output-file <file>  Write to the output file rather than stdout
  -c / --create-output-dirs  Automatically creates all parent directories for
                             files
  -i / --in-place            Update the Jsonnet file(s) in place
  --test                     Exit with failure if reformatting changed the
                             file(s)
  -n / --indent <n>          Number of spaces to indent by
                             (default 2, 0 means no change)
  --max-blank-lines <n>      Max vertical spacing (default 2, 0 means no change)
  --string-style <d|s|l>     Enforce double, single (default) quotes or 'leave'
  --comment-style <h|s|l>    # (h), // (s) (default), or 'leave'; never changes
                             she-bang
  --[no-]pretty-field-names  Use syntax sugar for fields and indexing
                             (on by default)
  --[no-]pad-arrays          [ 1, 2, 3 ] instead of [1, 2, 3]
  --[no-]pad-objects         { x: 1, y: 2 } instead of {x: 1, y: 2}
                             (on by default)
  --[no-]sort-imports        Sorting of imports (on by default)
  --[no-]use-implicit-plus   Remove plus signs where they are not required
                             (on by default)
  --version                  Print version

In all cases:
  <filename> can be - (stdin)
  Multichar options are expanded e.g. -abc becomes -a -b -c.
  The -- option suppresses option processing for subsequent arguments.
  Note that since filenames and jsonnet programs can begin with -, it is
  advised to use -- if the argument is unknown, e.g. jsonnetfmt -- "$FILENAME".