bug#56545: guix time-machine/shell throws "unsupported manifest format" error

[Ludovic Courtès]

Hi!

Maxim Cournoyer <maxim.cournoyer@gmail.com> scribes:

> and the channels.scm file:
>
> (list (channel
>        (inherit %default-guix-channel)
>        (commit
>         "ceeb2bfcaeb4380e01d26c8425e28b94ac13558a"))) ;2022-06-07
>
>
> and was surprised to be greeted with the following error:
>
> (repl-version 0 1 1)
> (exception %exception (non-self-quoting 140737300283024 "#<&message message: 
> \"unsupported manifest format\">"))
> /var/log/guix/drvs/j8/0wjfx7s7nxhcn0wjxfysnnv2knx0c1-guix-package-cache.drv 
> (END)
>
> What does it mean?  Which manifest is it referring to?

Commit 4ff12d1de7cd617b791996ee7ca1240660b4c20e introduced that bug,
which was fixed in c9fbd40785a99e13a59d8e530830ce85220a9871:

  https://issues.guix.gnu.org/56441

‘guix describe’ should show that you’re using a commit in that range.

The solution is to run ‘time-machine’ from a commit outside that range,
for instance with:

  guix time-machine -- time-machine -C channels.scm -- whatever

:-)

Ludo’.