Report an error if the user forgets to pass an argument to --trace.
Report an error if the user forgets to pass an argument to --trace.

ledger/ledger,duncanmortimer/ledger,duncanmortimer/ledger,jwakely/ledger,paulbdavis/ledger,duncanmortimer/ledger,jwakely/ledger,ledger/ledger,ledger/ledger,paulbdavis/ledger,duncanmortimer/ledger,jwakely/ledger,jwakely/ledger,duncanmortimer/ledger,afh/ledger,afh/ledger,afh/ledger,duncanmortimer/ledger,duncanmortimer/ledger,paulbdavis/ledger,paulbdavis/ledger,paulbdavis/ledger,jwakely/ledger,afh/ledger,ledger/ledger,ledger/ledger,paulbdavis/ledger,afh/ledger,paulbdavis/ledger,jwakely/ledger,jwakely/ledger