The command will raise an error if the simulation is already running.
When it is needed to reach a specified point in the simulation time one can use commands bp.time.run-until and bp.cycle.run-until that accept the -absolute flag. See the documentation of these command for information about their usage.
When used in a script, the run command will block further script execution until the simulation stops, similar to other CLI commands. This behavior can be overridden by the -non-blocking flag, that also has the side-effect of exiting all script execution. This flag is typically used at the end of a script to start simulation and still get an interactive command line.
Unlike other commands, the run and run-cycles commands will not block the command line when run interactively.
In script branches, the command will not block the script execution when run without the count argument. It will instead continue executing the next command as soon as the simulation has been started. When run with the count argument, the command will block until reaching the specified point in time.