The MultiIndexBlock destructor should correctly instantiate an UninterruptibleLockGuard by assigning it to a variable name that stays in scope.
Both renameCollection and compact commands use a MultiIndexBlock to rebuild indexes, which is not resilient to lock interrupts, but handles interruptibility through periodic calls to checkforInterrupt().
An UninterruptibleLockGuard should be used in both commands, similar to what is already done for the createIndexes command.
the jstestfuzz_interrupt_replication test suite has found that interrupting these commands can result in an fassert when cleaning up partially built indexes. For unknown reasons, the existing UninterruptibleLockGuard in the destructor does protect against this failure, and can just be removed.