This package depends on x11-libs/qt:3, which is scheduled for removal.
It should be removed if there is no Qt4 version.
There is a new Qt4 version of qmidiarp (0.3.9).
I have compiled it, but it gives an error:
qmidiarp: symbol lookup error: qmidiarp: undefined symbol: _Z13qFlagLocationPKc
Any chance of making an ebuild for this version (0.3.9)?