Drush crashes after "command dispatch complete"
Drush is running out of memory.

In the case of re/indexing search data via Search API, the item in that issue queue for this is Better memory usage on indexing.

To work around these sorts of issues, you can increase the amount of memory used by Drush, without touching the memory limit used by your Web server.  See Configuring php.ini for details.

In my case, in my drush.ini, I increased it from:


memory_limit = 256M


to:


memory_limit = 512M


...and it solved my Search API (re)indexing problem.