https://sn.1w6.org/file/clacke-20170920T072204-sxy9nym.html

Ran into this on another machine and here's something that actually works:

$ guix pull --url=http://git.savannah.gnu.org/cgit/guix.git/snapshot/guix-70bc608503f9029a065026a99ec45dbd0ec631c0.tar.gz

# that's when they added guile2.0-git

$ guix environment --ad-hoc guix guile2.0-git

... and then `guix pull` and `guix package -u` and you're back in the game.

I should tell guix-devel but I'm mentioning @cwebber and @dthompson instead because they might actually get around to it. #lazyweb

Context: The well-meant advice to upgrade guix with `guix pull --url=...snapshot...0.13.0.tgz` doesn't actually work for upgrading guix-0.12* to latest.