> py25_cairo and py_cairo cannot be installed at the same time:
>
> # port install py25-cairo
> ---> Activating py25-cairo 1.4.0_1
> Error: Target org.macports.activate returned: Image error: /opt/
> local/include/pycairo/pycairo.h is being used by the active py-
> cairo port. Please deactivate this port first, or use the -f flag
> to force the activation.
> Error: Status 1 encountered during processing.
Restated, the problem is that the meld port depends indirectly on
both py-cairo and py25-cairo, but the two cannot be installed
simultaneously. (I do not know whether it should be possible to
install arbitrary py-foo and py25-foo simultaneously.)