[Ash Kot]

I installed OpenFOAM on OSX, using one of famous github scripts, and it looks like, working perfect.
To test the installation, I decided to run entire tutorial section with Alltest option. As per the description of file, it should be able to run all tutorials in folder, for certain 1 time step and generate data of that time step. As it started running all the tutorials one by one, some of them got into Error, Of course the Error was regarding, Not setting up GNUplot.
but now the tutorials are just keep on running, and show this following message:
External: step 'someNumber(now it almost 110000)'
External: lock not present - taking control
External: sleeping for 1 secs to simulate external process
External: creating comms/data.in
./externalSolver: line 75: comms/data.in: no such file in directory
External: creating lock file comms/OpenFOAM.lock
touch: comms/OpenFOAM.lock: No such file in directory.

Since, I'm new to OpenFOAM, but now I'm moving from commercial software to Open Source.

Can anyone help me to explain?

How can I stop that, and if it's recurring error, what coding precautions I need to take.

Also I setup GNUPLOT with Homebrew How can I connect it with OpenFOAM so that, I can easily setup graph environment, for any case?