Running estimate ends in error: TypeError: Cannot read property '1' of undefined

[Rennzie]

I'm following the documentation to create my first tileset.

I've successfully run: mtsds --config path-to-geojson and got the expected config, recipe and .jsonl files.

I get this error when running mtsds --estimate as documented:

Estimating job size... this could take a while depending on your max zoom
TypeError: Cannot read property '1' of undefined
    at lineCover (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/@mapbox/tile-cover/index.js:231:30)
    at polygonCover (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/@mapbox/tile-cover/index.js:154:9)
    at getTiles (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/@mapbox/tile-cover/index.js:79:9)
    at Proxy.exports.indexes (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/@mapbox/tile-cover/index.js:53:12)
    at DestroyableTransform.<anonymous> (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/src/estimate.js:59:27)
    at DestroyableTransform.emit (events.js:223:5)
    at DestroyableTransform.EventEmitter.emit (domain.js:475:20)
    at addChunk (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/readable-stream/lib/_stream_readable.js:291:12)
    at readableAddChunk (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/readable-stream/lib/_stream_readable.js:278:11)
    at DestroyableTransform.Readable.push (/Users/seanrennie/Development/HUMMINGBIRD/mts-data-sync/node_modules/readable-stream/lib/_stream_readable.js:245:10)

I'm happy to help debug further but not sure where to go from here?

If I run mtsds --sync it works as expected.