10.1 Compilação cruzada

The commands supporting cross-compilation are proposing the --list-targets and --target options.

The --list-targets option lists all the supported targets that can be passed as an argument to --target.

$ guix build --list-targets
The available targets are:

   - aarch64-linux-gnu
   - arm-linux-gnueabihf
   - avr
   - i586-pc-gnu
   - i686-linux-gnu
   - i686-w64-mingw32
   - mips64el-linux-gnu
   - or1k-elf
   - powerpc-linux-gnu
   - powerpc64le-linux-gnu
   - riscv64-linux-gnu
   - x86_64-linux-gnu
   - x86_64-linux-gnux32
   - x86_64-w64-mingw32
   - xtensa-ath9k-elf

Targets are specified as GNU triplets (veja GNU configuration triplets em Autoconf).

Those triplets are passed to GCC and the other underlying compilers possibly involved when building a package, a system image or any other GNU Guix output.

$ guix build --target=aarch64-linux-gnu hello
/gnu/store/9926by9qrxa91ijkhw9ndgwp4bn24g9h-hello-2.12

$ file /gnu/store/9926by9qrxa91ijkhw9ndgwp4bn24g9h-hello-2.12/bin/hello
/gnu/store/9926by9qrxa91ijkhw9ndgwp4bn24g9h-hello-2.12/bin/hello: ELF
64-bit LSB executable, ARM aarch64 …

The major benefit of cross-compilation is that there are no performance penalty compared to emulation using QEMU. There are however higher risks that some packages fail to cross-compile because fewer users are using this mechanism extensively.