jvmdoc_gen: In the event of an exception, call get() on the remaining futures.
jvmdoc_gen: In the event of an exception, call get() on the remaining futures.

jvmdoc_gen: In the event of an exception, we want to call get() on the remaining futures because otherwise we get errors on exit when multiprocessing tries to kill them because what is dead may never die.

Ideally, we would kill them instead of waiting for them, but I don't see how to do that.

Testing Done:
./pants goal test tests/python/pants_test/tasks:jvmdoc_gen

It would be insanely difficult to write a real test for this, because the failure happens in an atexit handler.

Reviewed at https://rbcommons.com/s/twitter/r/1202/

digwanderlust/pants,benjyw/pants,sid-kap/pants,kslundberg/pants,qma/pants,jtrobec/pants,dturner-tw/pants,peiyuwang/pants,twitter/pants,areitz/pants,laurentgo/pants,fkorotkov/pants,lahosken/pants,dgomez10/xanon,gmalmquist/pants,peiyuwang/pants,sameerparekh/pants,UnrememberMe/pants,Gabriel439/pants,pantsbuild/pants,cevaris/pants,manasapte/pants,laurentgo/pants,kwlzn/pants,qma/pants,gmalmquist/pants,wisechengyi/pants,qma/pants,TansyArron/pants,sid-kap/pants,kwlzn/pants,fkorotkov/pants,pombredanne/pants,fkorotkov/pants,landism/pants,lahosken/pants,TansyArron/pants,square/pants,tdyas/pants,landism/pants,laurentgo/pants,sid-kap/pants,ericzundel/pants,cevaris/pants,Gabriel439/pants,scode/pants,UnrememberMe/pants,scode/pants,sid-kap/pants,tdyas/pants,di0spyr0s/pants,twitter/pants,foursquare/pants,gmalmquist/pants,laurentgo/pants,slyphon/pants,mateor/pants,Gabriel439/pants,sid-kap/pants,15Dkatz/pants,peiyuwang/pants,wisechengyi/pants,mateor/pants,megaserg/pants,slyphon/pants,dbentley/pants,sameerparekh/pants,manasapte/pants,baroquebobcat/pants,dgomez10/xanon,TansyArron/pants,15Dkatz/pants,dgomez10/xanon,pgroudas/pants,ity/pants,pgroudas/pants,twitter/pants,15Dkatz/pants,square/pants,ericzundel/pants,jessrosenfield/pants,dbentley/pants,twitter/pants,UnrememberMe/pants,slyphon/pants,dturner-tw/pants,cevaris/pants,sid-kap/pants,areitz/pants,lahosken/pants,gmalmquist/pants,landism/pants,benjyw/pants,TansyArron/pants,jtrobec/pants,jtrobec/pants,wisechengyi/pants,jsirois/pants,peiyuwang/pants,sameerparekh/pants,megaserg/pants,twitter/pants,jtrobec/pants,jessrosenfield/pants,fkorotkov/pants,kwlzn/pants,square/pants,dbentley/pants,sameerparekh/pants,megaserg/pants,tdyas/pants,cevaris/pants,manasapte/pants,qma/pants,tdyas/pants,foursquare/pants,digwanderlust/pants,slyphon/pants,manasapte/pants,pgroudas/pants,di0spyr0s/pants,peiyuwang/pants,twitter/pants,cevaris/pants,lahosken/pants,kwlzn/pants,baroquebobcat/pants,fkorotkov/pants,gmalmquist/pants,ity/pants,mateor/pants,megaserg/pants,15Dkatz/pants,pantsbuild/pants,pombredanne/pants,scode/pants,wisechengyi/pants,scode/pants,ity/pants,mateor/pants,kwlzn/pants,di0spyr0s/pants,Gabriel439/pants,megaserg/pants,di0spyr0s/pants,ericzundel/pants,qma/pants,mateor/pants,landism/pants,foursquare/pants,lahosken/pants,megaserg/pants,manasapte/pants,tdyas/pants,jsirois/pants,qma/pants,areitz/pants,dbentley/pants,landism/pants,baroquebobcat/pants,tejal29/pants,manasapte/pants,tejal29/pants,tejal29/pants,areitz/pants,foursquare/pants,tdyas/pants,15Dkatz/pants,UnrememberMe/pants,UnrememberMe/pants,kslundberg/pants,square/pants,pantsbuild/pants,ity/pants,ericzundel/pants,dgomez10/xanon,baroquebobcat/pants,dgomez10/xanon,ericzundel/pants,dgomez10/xanon,kwlzn/pants,jessrosenfield/pants,mateor/pants,kslundberg/pants,dturner-tw/pants,dturner-tw/pants,wisechengyi/pants,tdyas/pants,jessrosenfield/pants,pombredanne/pants,scode/pants,lahosken/pants,benjyw/pants,twitter/pants,jessrosenfield/pants,gmalmquist/pants,foursquare/pants,baroquebobcat/pants,slyphon/pants,jtrobec/pants,jessrosenfield/pants,foursquare/pants,pombredanne/pants,ity/pants,benjyw/pants,ericzundel/pants,dgomez10/xanon,pantsbuild/pants,15Dkatz/pants,landism/pants,dbentley/pants,lahosken/pants,di0spyr0s/pants,UnrememberMe/pants,pantsbuild/pants,tejal29/pants,wisechengyi/pants,gmalmquist/pants,foursquare/pants,baroquebobcat/pants,digwanderlust/pants,kslundberg/pants,pgroudas/pants,TansyArron/pants,ericzundel/pants,digwanderlust/pants,dgomez10/xanon,dbentley/pants,peiyuwang/pants,peiyuwang/pants,di0spyr0s/pants,dturner-tw/pants,sameerparekh/pants,benjyw/pants,laurentgo/pants,cevaris/pants,areitz/pants,slyphon/pants,lahosken/pants,dgomez10/xanon,mateor/pants,wisechengyi/pants,fkorotkov/pants,dbentley/pants,scode/pants,peiyuwang/pants,areitz/pants,jessrosenfield/pants,pombredanne/pants,dgomez10/xanon,dturner-tw/pants,kslundberg/pants,manasapte/pants,twitter/pants,digwanderlust/pants,benjyw/pants,twitter/pants,pombredanne/pants,megaserg/pants,tejal29/pants,ity/pants,cevaris/pants,areitz/pants,sid-kap/pants,sameerparekh/pants,pombredanne/pants,kslundberg/pants,jtrobec/pants,TansyArron/pants,ericzundel/pants,dgomez10/xanon,fkorotkov/pants,landism/pants,foursquare/pants,UnrememberMe/pants,dturner-tw/pants,pgroudas/pants,qma/pants,slyphon/pants,wisechengyi/pants,15Dkatz/pants,pantsbuild/pants,Gabriel439/pants,sameerparekh/pants,baroquebobcat/pants,baroquebobcat/pants,pgroudas/pants,kwlzn/pants,benjyw/pants,landism/pants,baroquebobcat/pants,wisechengyi/pants,tdyas/pants,di0spyr0s/pants,UnrememberMe/pants,pantsbuild/pants,digwanderlust/pants,UnrememberMe/pants,laurentgo/pants,scode/pants,jsirois/pants,foursquare/pants,kslundberg/pants,tdyas/pants,15Dkatz/pants,mateor/pants,Gabriel439/pants,fkorotkov/pants,jtrobec/pants,Gabriel439/pants,ity/pants,TansyArron/pants