Hello,
Guix.

I solved my problem. Please use this new patch,
which will be attached to this message.

I must apologize for my carelessness.

I unnecessary added dependency cycle between elogind and polkit.
At the time I added polkit, as input dependency of elogind,
I was looking at service extension graph and
mistook it for dependency graph I had opened at that same time,
that was foolish of me. :(

My system compiled fine with newer version of elogind,
because the polkit my system used deepened on
older version of elogind.
But that meant that I had trouble when I tried to
replace old elogind in guix repository with the newer elogind version.

Problem is now solved.
I spent so much time looking for the cause of this problem. :(
But it was fun. And I gained useful experience. :)

I now know how guix behaves when I try to evaluate
derivation that has dependency cycle,
it hangs not printing anything and
keeps increasing RAM memory usage. :)

Thank you, for your patience.
I will wait for the official release of elogind version 239.2
before sending the modified version of this patch to guix-patches.
The 239.2 version of elogind should be released in a few days,
but that is only my prediction.

Stefan.