qgis: request to set gdal dependency to +postgresql94 variant

[garethsimons@…]

Some QGIS plugins fail with the current qgis port. These issues can be fixed by installing gdal with the +postgresql94 variant. Would be nice to have this by default.

[ryandesign (Ryan Carsten Schmidt)]

MacPorts doesn't have the ability for one port to declare a dependency on a variant of another port. That's #126. It only has the ability to declare a dependency on another port.

gdal has many database variants. It might not be appropriate for us to make the postgresql94 variant appear more important than the others by turning it on by default.

However, the qgis port could either require the postgresql94 variant of gdal, using the require_active_variants proc in the active_variants 1.1 portgroup, or if it's more of a recommendation and not a requirement, the qgis port could display notes to the user if gdal isn't installed with that variant. (There should be some helper functions in active_variants 1.1 that can be used to determine what variants the other port is installed with.)

[Veence (Vincent)]

I will look after that. At least, I should make sure that the gdal and the QGis variant are consistent.

[Veence (Vincent)]

gdal has no default variant for postgresql. Postgresql 9.5 is now the default for both postgis and qgis. Tell me if you want me to make it also a default for gdal.