bug#56441: guix time-machine broken by profiles speed-up

[zimoun]

Hi,

Bug#55499 [1] is fixed by 4ff12d1de7cd617b791996ee7ca1240660b4c20e.
However, because the manifest version is going from 3 to 4 with new
fields, the new Guix cannot builds the old Guix.

Commit 4ff12d1de7cd617b791996ee7ca1240660b4c20e is not able to go to its
parent 9b8c442b254b82196fe2492142b3c3bbbd891a1b.

--8<---------------cut here---------------start------------->8---
$ git rev-parse 4ff12d1de7^
9b8c442b254b82196fe2492142b3c3bbbd891a1b

$ guix time-machine --commit=4ff12d1de7 -- time-machine --commit=9b8c442b25 -- 
help
Updating channel 'guix' from Git repository at 
'https://git.savannah.gnu.org/git/guix.git'...
Computing Guix derivation for 'x86_64-linux'... \
The following derivation will be built:
  /gnu/store/r5qk23fibxn5ryd2k7b8qkbryqv4m3ds-profile.drv

building package cache...
|builder for 
`/gnu/store/19nk2x26s0dp68r7d36ifbg0ck0q3xps-guix-package-cache.drv' failed to 
produce output path 
`/gnu/store/axqgrls563slnp76x60dqlv7sdwcm2ly-guix-package-cache'
build of /gnu/store/19nk2x26s0dp68r7d36ifbg0ck0q3xps-guix-package-cache.drv 
failed
View build log at 
'/var/log/guix/drvs/19/nk2x26s0dp68r7d36ifbg0ck0q3xps-guix-package-cache.drv.gz'.
cannot build derivation 
`/gnu/store/r5qk23fibxn5ryd2k7b8qkbryqv4m3ds-profile.drv': 1 dependencies 
couldn't be built
guix time-machine: error: build of 
`/gnu/store/r5qk23fibxn5ryd2k7b8qkbryqv4m3ds-profile.drv' failed
--8<---------------cut here---------------end--------------->8---


1: <https://issues.guix.gnu.org/55499>



Cheers,
simon