time nice -19 ~/src/guix/pre-inst-env guix system build ~/config.scm
--system=x86_64-linux

building
/gnu/store/27raas2bj7sck7vgiicfr2g4h6qrd6ga-activate-service.drv...
@ unsupported-platform
/gnu/store/27raas2bj7sck7vgiicfr2g4h6qrd6ga-activate-service.drv
x86_64-linux
while setting up the build environment: a `x86_64-linux' is required to
build
`/gnu/store/27raas2bj7sck7vgiicfr2g4h6qrd6ga-activate-service.drv', but
I am a `i686-linux'
builder for
`/gnu/store/27raas2bj7sck7vgiicfr2g4h6qrd6ga-activate-service.drv'
failed with exit code 1
build of
/gnu/store/27raas2bj7sck7vgiicfr2g4h6qrd6ga-activate-service.drv failed
View build log at
'/var/log/guix/drvs/27/raas2bj7sck7vgiicfr2g4h6qrd6ga-activate-service.drv.bz2'.
cannot build derivation
`/gnu/store/da24a831db5lv0z60kyh1drz2sw20q88-activate.drv': 1
dependencies couldn't be built
building
/gnu/store/hkjn3n1q91dnvvq5nmjs8kr2lkw4fww3-module-import-compiled.drv...
cannot build derivation
`/gnu/store/fxvgakgpmhpq1abhqnrxzirgjkmns7nb-boot.drv': 1 dependencies
couldn't be built
building
/gnu/store/jqp8g5anxc2zqisb2hv4gd8rrih0z4mj-module-import.drv...
cannot build derivation
`/gnu/store/wm9blmyzw7vsxfbdd1rpx8f9k5qm2hvf-system.drv': 1 dependencies
couldn't be built
guix system: error: build failed: build of
`/gnu/store/wm9blmyzw7vsxfbdd1rpx8f9k5qm2hvf-system.drv' failed



-- 
Cheers 
Swedebugia