Raise exception instead of returning magical number from 'arc anoid'
Raise exception instead of returning magical number from 'arc anoid'

Summary: how do I python

Test Plan: help

Reviewers: alanh

Reviewed By: alanh

CC: aran

Differential Revision: https://secure.phabricator.com/D3245

wharris/arcanist,KieranHayes/arcanist,sneakpeeq/arcanist,kevinseelbach/arcanist,fivestars/arcanist,eSpark/arcanist,sneakpeeq/arcanist,hach-que/arcanist,coursera/arcanist,phacility/arcanist,phacility/arcanist,r4nt/arcanist,julkiewicz/arcanist,dguo-coursera/arcanist,fivestars/arcanist,PageUpPeopleOrg/arcanist-patches,sneakpeeq/arcanist,Khan/arcanist,aik099/arcanist,haskell-infra/arcanist,hach-que/arcanist,eSpark/arcanist,hach-que/arcanist,alexmv/arcanist,kevinseelbach/arcanist,Symplicity/arcanist,phacility/arcanist,fivestars/arcanist,haskell-infra/arcanist,phacility/arcanist,Khan/arcanist,sneakpeeq/arcanist,alexmv/arcanist,jra3/arcanist,r4nt/arcanist,memsql/arcanist,folsom-labs/arcanist,folsom-labs/arcanist,KieranHayes/arcanist,zhihu/arcanist,codelabs-ch/arcanist,julkiewicz/arcanist,codelabs-ch/arcanist,calblueprint/arcanist,folsom-labs/arcanist,codelabs-ch/arcanist,chundongwang/arcanist,memsql/arcanist,wharris/arcanist,dguo-coursera/arcanist,zhihu/arcanist,wxstars/arcanist,haskell-infra/arcanist,wharris/arcanist,uber/arcanist,PageUpPeopleOrg/arcanist-patches,wikimedia/phabricator-arcanist,zhihu/arcanist,kevinseelbach/arcanist,r4nt/arcanist,hach-que/arcanist,wxstars/arcanist,uber/arcanist,alexmv/arcanist,aik099/arcanist,haskell-infra/arcanist,dguo-coursera/arcanist,coursera/arcanist,coursera/arcanist,jra3/arcanist,chundongwang/arcanist,calblueprint/arcanist,phacility/arcanist,memsql/arcanist,PageUpPeopleOrg/arcanist-patches,calblueprint/arcanist,jra3/arcanist,alexmv/arcanist,memsql/arcanist,codelabs-ch/arcanist,uber/arcanist,uber/arcanist,kevinseelbach/arcanist,eSpark/arcanist,jra3/arcanist,wikimedia/phabricator-arcanist,PageUpPeopleOrg/arcanist-patches,codelabs-ch/arcanist,coursera/arcanist,wikimedia/phabricator-arcanist,Symplicity/arcanist,aik099/arcanist,fivestars/arcanist,zhihu/arcanist,wxstars/arcanist,Symplicity/arcanist,eSpark/arcanist,wharris/arcanist,folsom-labs/arcanist,dguo-coursera/arcanist,Khan/arcanist,wikimedia/phabricator-arcanist,chundongwang/arcanist,calblueprint/arcanist,chundongwang/arcanist,KieranHayes/arcanist,Khan/arcanist,KieranHayes/arcanist,Symplicity/arcanist,r4nt/arcanist,julkiewicz/arcanist,aik099/arcanist,wxstars/arcanist,julkiewicz/arcanist