Communication error: libc.dylib - connecting to server from within Maya 2018 update 5 on OSX



I’m seeing the following error when trying to setup the Maya submission scripts
Error: Failed to establish connection to due to a communication error: libc.dylib (Deadline.Configuration.DeadlineConfigException)
This is with Maya 2018 update 5 on OSX Mojave (10.14).

I stripped out the core Mel commands to make the situation reproducible. Those commands are as follows
string $deadlineBin = getenv "DEADLINE_PATH";
string $deadlineCommand = $deadlineBin + “/deadlinecommand”;
string $command = “-GetRepositoryPath”;
string $deadlineCommandString = “call “” + $deadlineCommand + “” " + $command + " 2> nul”;
system( $deadlineCommand + " " + $command );

Running the same command from a shell produces the expected output
bash-3.2$ ./deadlinecommand -GetRepositoryPath

This is with an installation of Deadline

Any suggestions?