On 2022-10-03 00:10, zimoun wrote:
[..]
Let try the converse,
--8<---------------cut here---------------start------------->8---
$ guix time-machine --commit=729ce5f -- package -i hello -p /tmp/old
$ cat /tmp/old/manifest | grep -A 1 '(manifest'
(manifest
(version 4)
$ guix package --list-generations -p /tmp/old
Generation 1 oct. 02 2022 18:53:10
hello 2.10 out /gnu/store/xg67cpxq2p6q7wn4y2z194pndwdymhpf-hello-2.10
Generation 2 oct. 02 2022 21:25:11 (current)
+
hello 2.12.1 out /gnu/store/s5pd3rnzymliafb4la5sca63j86xs0y0-hello-2.12.1
- hello 2.10
out /gnu/store/xg67cpxq2p6q7wn4y2z194pndwdymhpf-hello-2.10
--8<---------------cut here---------------end--------------->8---
This profile /tmp/old is thus converted from version 3 to version 4,
and
then, reusing old version of Guix fails,
--8<---------------cut here---------------start------------->8---
$ guix time-machine --commit=7e8e070 -- package -i hello -p /tmp/old
guix package: error: unsupported manifest format
--8<---------------cut here---------------end--------------->8---
Well, I do not know if a fix is possible. The issue is a
backward compatibility issue.
Hi,
Thanks for the clarification.
I imagine it would be possible to give it a dirty fix, approximately as
you just showed with /tmp/old, if you also just readd the default
profile's currently installed packages to it at the end. So, if using
~/.guix-profile, it would be something like:
1. Say your ~/.guix-profile is at commit=XYZ
2. build a NEW profile with the old package ONLY, from commit=ABC (as in
/tmp/old)
3. guix pull /tmp/old "back" to commit=XYZ
4. install remaining packages that was in your ~/.guix-profile to
/tmp/old.
5. mv the ~/.guix-profile symlink to /tmp/old.
( /tmp/old should just be in /var/guix/profiles/per-user/$USER as normal
)
Building a new package generation like this would not be the same as
usual, cuz the currently installed packages may come from different guix
revisions. That might be a dealbreaker for fixing it. I do think it's
very sad though, that the time-machine is kind of broken whenever the
manifest gets a new version, with no hint even to the user how to find a
solution.
Best regards,
David
