bug#62936: [core-updates] pre-inst-env no longer works

[Brian Cully via Bug reports for GNU Guix <bug-guix@gnu.org>]

Josselin Poiret <dev@jpoiret.xyz> writes:

> Ran into this problem myself, here's the reason and the fix:
>
> We build a modified `guile` executable in the source tree (for 
> reasons),
> and use that to run guix.  Note that it is only added to PATH by
> ./pre-inst-env!  That guile executable is linked against glibc, 
> and so
> after upgrading to a newer glibc, it isn't rebuilt (I don't know 
> how
> autotools cope with external dependencies getting updated).  So 
> glibc
> 2.33 gets loaded, and once (gcrypt) tries to open the libgcrypt 
> library,
> it fails because that newer library needs at least glibc 2.34. 
> The
> solution is just to `rm guile` inside of the checkout and run 
> `make`
> again.

With a lot of help on IRC, the culprit was discovered: you *must* 
run ‘guix pull --branch=core-updates’ to update your current 
profile's guix. This is because guix does not update itself 
without the pull.

Without this step, the guix in your user profile will keep around 
its old rules about which C compiler to use, which, in turn, pulls 
in the old glibc, which causes the error I initially reported.

-bjc