The build system does not provide means for a proper staged install. Nor can one do an out-of-source build.
It may be too much trouble to redo the whole build system (at least if any compatibility with Windows remain desired). But we can add a script for staged install, using oipatch; see my Gentoo ebuild that does this. And out-of-source builds might be faked by symlinking or copying files.
The build system does not provide means for a proper staged install. Nor can one do an out-of-source build.
It may be too much trouble to redo the whole build system (at least if any compatibility with Windows remain desired). But we can add a script for staged install, using oipatch; see my Gentoo ebuild that does this. And out-of-source builds might be faked by symlinking or copying files.