Downloads caused by guix package -u Vs guix system reconfigure

[Laurence Rochfort]

Hello all,

Relatively new guix system user.

On a new install of guix system, I did a "guix pull && guix package -u".

It said I was up-to-date.

I then did a "guix system reconfigure", and that caused a download of 640Mb
of substitutes.


Could somebody please help me understand why it prompted such different
behaviour?

Many thanks,
Laurence