Question: I just got a new Mac Pro with OS X 10.9. When I run:

```
brew doctor

```

I get the warning:

```
Warning: You have MacPorts or Fink installed:
/opt/local/bin/port

This can cause trouble. You don't have to uninstall them, but you may want to 
temporarily move them out of the way, e.g.
sudo mv /opt/local ~/macports

```

I didn't install MacPorts or Fink, why do I get the warning?

Answer: 
Note that some 3rd-party packaging tools may sometimes automatically install MacPorts. I recall RVM does that (or at least used to, I don't know the current state), so while you're not aware of actually installing it manually, it might still be there.

If you move `/opt/local` to a different location that might break whatever pulled in MacPorts in the first place.
The error reports that `/opt/local/bin/port` exists.

* If you haven't installed it, the error is shown because the path exists. Move the executable:

```
sudo mv /opt/local/bin/port ~/Desktop

```
* If you have installed it, you can run the command given:

```
sudo mv /opt/local ~/macports

```