Re: How to install previous versions?

[zimoun <zimon.toutoune@gmail.com>]

Hi,

On Fri, 9 Oct 2020 at 19:19, Zelphir Kaltstahl
<zelphirkaltstahl@posteo.de> wrote:

> http://data.guix.gnu.org/repository/1/branch/master/package/python-redis.

On this web page, you can click on the date: first commit and last
commit known to have this version.  You can even see the status
(build, failed, pending, etc.) on this web page (appending
'output-history')

http://data.guix.gnu.org/repository/1/branch/master/package/python-redis/output-history

For example, clicking leads to:

http://data.guix.gnu.org/revision/f5111b4d2b982d58387188bc3018e4dd2e9a9d4f

And this gives you the commit with 'python-redis@3.8', using the command:

  guix time-machine --commit=f5111b \
         -- environment --ad-hoc python-redis python \
         -- python


> So how would I need to write my manifest.scm or my one-liner to get back
> to that older version?

The best is to write a manifest file, say manifest.scm containing the
package you need:

--8<---------------cut here---------------start------------->8---
(specfications->manifest
  (list
   "python-redis"
   "python"
   "foo"
   "bar"
   "etc"))
--8<---------------cut here---------------end--------------->8---

The other no-so-said is to track "guix describe", you *should* _track_
the file channels.scm:

   guix describe -f channels.scm

Then later or on another machine, you simply run the command:

   guix time-machine -C path/to/channels.scm \
          -- <subcommand> -m path/to/manifest.scm <options>


Hope that helps,
simon