Given a replica set with config like

{
  _id: 'rs',
  members: [
    {
      _id: 0,
      host: '…',
      priority: 3,
    },
    {
      _id: 1,
      host: '…',
      priority: 1,
    },
    {
      _id: 2,
      host: '…',
      priority: 0,
      hidden: true,
      buildIndexes: false,
    },
  ]
} 

Building indexes on replica-set with default commitQuorum (votingMembers) seems to wait for build on member that doesn't build indexes (due to replica-set configuration)

I have to lower commitQuorum to majority, otherwise createIndex command doesn't finish.

votingMembers commitQuorum should mean: all data-bearing index-building voting replica set members.