Error: Unable to execute port: can't create directory "/opt/local/var/macports/build": permission denied

[batchelordb@…]

This is my first attempt to install a port. Things like "port list", "port search" and "port info" work fine. What I tried was: ~ $ port install -v pgplot +darwin_i386 +aqt +demos

and what I got was: Error: Unable to execute port: can't create directory "/opt/local/var/macports/build": permission denied

I guess the permissions are set wrong. But I hesitate to tinker with them since the /opt directory and its subdirectories are installed by MacPorts.

I looked in FAQ but didn't find anything.

[pmagrath@…]

As per ​http://guide.macports.org/#using.port.install, you need to run port install commands with sudo. So, "sudo port install -v pgplot +darwin_i386 +aqt +demos".

Maybe this should be made clear in the error message when port install is invoked and runs into permissions errors like this?

[febeling@…]

I think we should simply close such issues, it should be reasonably clear that you need superuser rights to install software, and for shell commands that's sudo.