Disclaimer: this bug has been filed in a semi-automated manner.
When emerging the package x11-libs/qt-gui-4.8.2, the following elog messages are displayed:
* Starting with Qt 4.8, you may choose the active Qt Graphics System
* by using a new eselect module called qtgraphicssystem.
* Run `eselect qtgraphicssystem` for more information.
Such messages should only be displayed when the package is upgraded from an old enough package (and possibly for new installs).
These situations can be checked in the ebuild as follows:
if has_version '<x11-libs/qt-gui-1.0'; then
Or, if the message should also be displayed for new installs:
if !has_version 'x11-libs/qt-gui' || has_version '<x11-libs/qt-gui-1.0'; then
Remember to replace 1.0 with the right version number.
See the tracker bug 440214 for more details.
BTW we have REPLACING_VERSIONS and REPLACED_BY_VERSION in EAPI >= 4.
The message has been removed altogether. It was useless anyway.