Can't get past this error.

Hi, have Atom with platformio to use to edit and compile Marlin 2.0. I am having a problem getting it to see the location that I want the compiled file to be placed with Upload_port. It was working briefly and is now not working and I don’t know why. Have used it successfully with Upload_port = volumes/marlin but it no longer works with that. This is being used with a mac so any answers with that in mind would be welcome. TIA.

I have no experience in this … but as a very wild guess should you not have forward slash preceding dir path ? Does developer tools shed any light?