patch.sh error - no such table: map, no such table: images

[slutske22]

I am trying to use the patch script to patch 2 .mbtiles files together. I run

./patch.sh source.mbtiles destination.mbtiles

And I get the output error

Parse error near line 6: no such table: map
Parse error near line 7: no such table: images

If I unpack the mbtiles and look at their metadata.json, the source has an empty object in its metadata, and the destination has some metadata:

{
    "version": "1.2",
    "bounds": "119.008200,17.000023,123.000192,24.000000",
    "description": "description",
    "type": "baselayer",
    "name": "name",
    "format": "png",
    "minzoom": "2",
    "maxzoom": "13"
}

I'm not sure I understand why the patch script is giving me this error?