Hunspell stemmer requires gigantic (for the task) amounts of memory to load dictionary/rules files.
For example loading a 4.5 MB polish dictionary (with empty index!) will cause whole core to crash with various out of memory errors unless you set max heap size close to 2GB or more.
By comparison Stempel using the same dictionary file works just fine with 1/8 of that (and possibly lower values as well).
Sample error log entries: