If you set MAKEOPTS="-jX" to a relatively high number (e.g. 6), this build can fail. An example: gantu ~ $ sudo MAKEOPTS="-j6" emerge -1 qemu-kvm ... >>> Compiling source in /var/tmp/portage/app-emulation/qemu-kvm-0.13.0/work/qemu-kvm-0.13.0 ... make -j6 GEN x86_64-softmmu/config-devices.mak GEN x86_64-linux-user/config-devices.mak GEN i386-softmmu/config-devices.mak GEN i386-linux-user/config-devices.mak GEN config-all-devices.mak GEN qemu-img-cmds.texi GEN qemu-monitor.texi GEN qemu-tech.html GEN qemu-options.texi GEN qemu-nbd.8 GEN QMP/qmp-commands.txt GEN config-host.h GEN qemu-img-cmds.h CC cmd.o In file included from qemu-aio.h:17, from cmd.c:27: qemu-common.h:5:25: error: config-host.h: No such file or directory In file included from qemu-aio.h:17, from cmd.c:27: qemu-common.h:61: error: redefinition of 'struct iovec' make: *** [cmd.o] Error 1 If I had to venture a guess, it would be that the "GEN config-host.h" target needs to complete before compilation begins.
*** This bug has been marked as a duplicate of bug 343175 ***
