FYI - I am trying to contact (via a site "MacPorts") the maintainer of Gpredict and hope to get a solution there. Anyway, I have been running Gpredict for several years on various Macs. i am now running 1.3 on a Mac Mini and a MacBook Pro with fairly recent OS.
I use a site, MacPorts, to install Gpredict - and have done that several times on various computers. So today I saw Gpredict 2.0 appear on MacPorts and went to install. No joy, various error messages about dependencies.
So I pretended to be a real Unix guy and went to the MacPorts IRC and chatted there - some folks helped me work through a few issues but ultimately the installation did not work. They are trying to help me contact someone named zapman who is the maintainer - but that person does not answer emails.
Hopefully some changes to the installation scripts will be made over the next week or so. I will wait a week and try again - when I succeed I'll come back here with a report.