Q:

Making MacPorts Think A Dependency Is Already Installed

I like to install some packages by hand that are also available through MacPorts. When I do this MacPorts still wants to install that package even though its binaries are in the path.
Is there any way to install let's say Python without MacPorts and than install a package that depends on Python via MacPorts without installing MacPorts Python?

A:

No, this is not supported by any standard way. The maintainers of MacPorts care a lot about reproducibility of the builds and thus, MacPorts does not allow any other software to fulfil the requirement.
These entries in the MacPorts FAQ should answer this question in more detail:

Will MacPorts link to system libraries rather than its own?
Why is MacPorts using its own libraries?

