--vmaf-res inputres doesn't work

[esiefker]

The --help text says inputres is a valid argument to --vmaf-res

      --vmaf-res <VMAF_RES>
          Resolution used for VMAF calculation
          
          If set to inputres, the output video will be scaled to the resolution of the input video.
          
          [default: 1920x1080]

This does not work for me. av1an fails after scene detection with this error

ERROR av1an_core::broker: [chunk 39] Target Quality failed after 3 tries on chunk 39:
encoder crashed: exit status: 234
stdout:

stderr:
        [Parsed_scale_0 @ 0x5556f9276b40] Invalid size 'inputres'
        [AVFilterGraph @ 0x5556f9275dc0] Error initializing filters
        Error : Invalid argument

source pipe stderr:

The log file is attached.

target93.log