bug#41604: guix pull impossible after rebasing a local repository

[John Soo]

Hello,

zimoun <zimon.toutoune@gmail.com> writes:

> Is "guix pull --commit=1444040933 --allow-downgrades" not working for you?

Yeah guix pull --commit=1444040933 --allow-downgrades failed.

> What do you mean?  An option for you or an option of "guix pull"?
> Ah my bad, it is "--roll-back".  The double "--roll-back" and
> "--rollback" options is only allowed with "guix package".  Thank you
> for the notification. :-)

Ah, nice! roll-back helped me work around the problem. Very helpful,
thanks!

> Hehe! Dangerous zone. :-)

I think I found that out, haha!


> Personally, I keep clean ~/.config/guix/current by always pulling from
> origin/master.
> Then I have, as you, a local clone where I rebase, commit etc. But I
> only pull to another profile than the default one, to avoid similar
> situations as you currently are. ;-)
>
>    /path/to/what-i-mean/bin/guix pull --url=/pah/local/clone
> --branch=kikoo -p /path/to/next
>
> and I have some channels files under ~/.config/guix/ to simply some
> regular, e.g.,
>
>    guix pull -C ~/.config/guix/extra.scm -p /path/to/extra
>    /tmp/extra/bin/guix install foo -p /tmp/test
>
> And so "guix pull" always works.
> Anyway! :-)

Nice!  I like the idea of having a "next" profile.

I guess that makes me wonder what the desired specification is.
There is a lot of problem space to explore.  As a user I would want to
be able to take my local patches as "the real truth".

Because guix has a linear git history, that means the user needs to
always rebase.  Often I have patches open for months that I am currently
testing and working on. It would be convenient for me to be able to guix
pull into my default user profile.

On the other hand, as you point out, using a hash that disappears from
the git history is dangerous. The git history no longer tracks the guix
pull history and then there may exist pulls in history that may never be
recoverable.

There seems to be some existing support for the rebasing into the
default profile since branches are allowed as references in the channels
configuration. Has the rebase use case been discussed before? Oh, also,
history items can be deleted in other places with --delete-generations
and friends.  I am not sure what to classify this problem, bug or
something else.

What do you think?

- John