Does the virt-manager port have additional requirements?

[Ralph Seichter]

* Ken Cunningham:

> We are having discussions about automating this by making the server a
> dependency of the x11 subsystem, but consensus eludes us to date.

I have opened a pull request [1] with an enhanced long description for
the virt-manager port. I used "port info" myself, but there was no hint.
Hopefully the PR will prevent others from wasting time in the future.

[1] https://github.com/macports/macports-ports/pull/7271

-Ralph