Guys, shouldn't QMAKESPEC be set to linux-g++-64 on amd64? Some people suggest:
http://lists.trolltech.com/qt-interest/2002-10/thread00806-0.html (see message 6)
and some programs (qtiplot) use in .pro files:
This breaks multilib (see http://bugs.gentoo.org/299769#c20). If this is not suggested solution I can set QMAKESPEC manually on amd64 for qtiplot or alternatively it possible to use following workaround:
http://lists.trolltech.com/qt-interest/2005-11/thread00305-0.html (message 4)
We could change it, but it would cause more problems than benefits (e.g. the possible multilib incompatibility that you mentioned). The default mkspec is relevant only to qmake-based projects ran with default configuration.
Instead we're about to pass correct mkspec as a qmake parameter in eqmake4, so when compiling with Portage in 32-bit environment it would be linux-g++ (or linux-g++-32, we'll investigate it further) and, respectively, linux-g++-64 for amd64 environment.
So the issue itself will be fixed for compilation with Portage, but by other means. By the way, the default mkspecs is set to linux-g++ for instance on amd64 Debian and Ubuntu. Users can still adjust the symlink to their liking.