Hello!

Finally it succeeded. Thanks to everyone who has answered my countless
questions on the mailing list and IRC!

GNU Hello - /gnu/store/98wc63drnc5iwkcclls91iz181mmiv7c-hello-2.10
(natively built with: ./pre-inst-env guix build hello)

I used Gentoo (https://wiki.gentoo.org/wiki/Handbook:PPC64) as a base
PowerPC 64-bit big endian system. (precisely IBM POWER9)

source:

https://gitlab.com/lle-bout/guix - commit
f47e761a10675b05b07107035d5024618267a3ad (current master at time of writing)

bootstrap binaries:

https://gitlab.com/lle-bout/guix-bootstrap - commit
b017c0459bc65a53203eb056998be8abd7778e4a (current master at time of
writing) - currently it's unclear from which revision the bootstrap
binaries come from, a rebuild of all the binaries from the latest ported
guix's revision is pending.

How to build bootstrap binaries:

On a system where GNU Guix already works:

./pre-inst-env guix build --target=powerpc64-linux-gnu bootstrap-tarballs

Next steps are getting things to work on powerpc64le-linux-gnu (shouldnt
be too hard now) then rebase everything onto core-updates!

Leo