Created attachment 456012 [details] Build.log, emerge_pqv.log, build info ./arch/x86/include/asm/realmode.h:66:2: error: implicit declaration of function ‘ALIGN’ [-Werror=implicit-function-declaration] see attached log files
I can confirm this. On two machines I couldn't build latest virtualbox-modules-5.1.10 with gentoo-sources-4.9.0 due to this error.
*** This bug has been marked as a duplicate of bug 602420 ***