I'm unable to install QGIS on lubuntu (LXDE desktop). This is what it says on the terminal:
Package qgis is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'qgis' has no installation candidate
On previous attempt of installation the problem was in absence(?) of QT environment (if I understood correctly).