Indexer gives error for multiple stopwords files

When I run sudo indextool --check geolocations, I get a failure:
checking index 'geolocations'... FAILED, unable to open stopwords '/usr/share/manticore/stopwords/en,/usr/local/manticore/data/stopwords.txt': No such file or directory

It looks like both stopwords files are used when I run Manticore queries, so maybe this is a bug with the indexer?

If I use only 1 of the above stopwords files in my manticore.conf the indexer does not show a failure.

Is this the correct way to use multiple stopwords files?

Note: The path to both of the stopwords files is correct.

however manual says stopwords file list should be space separated. Could you change your config reindex data and make sure all works as expected?

Yep, swapping the comma for space fixed it.
I was thrown by the examples e.g. stopwords = 'en, it, ru'.