Hi,

Ludovic Courtès <ludo@gnu.org> skribis:

> Another option (thinking out loud):
>
>   • in ‘package-cache-file’, unconditionally generate a v3 profile (we
>     could add a ‘version’ field to <profile> etc.);
>
>   • likewise in ‘channel-instances->derivation’.

The patches below do that.  As discussed on IRC, it’s not pretty but
it’s pragmatic.

Tested with:

  ./pre-inst-env guix time-machine \
    --commit=85a5110de79f4fe9fd822ede3915654ee699d6c5 -- describe

How does that sound?

> Problem: it doesn’t address the case where you install the ‘guix’
> package in a regular profile (I think?).

I haven’t yet checked whether this is the case.

Ludo’.