bootstrapping scenario for a package

[Andy Tai <atai@atai.org>]

Hi, I was trying to update mono to the current release version.  The
build step as documented actually says to download a minimal C#
compiler from the mono site which is then used to compile the rest of
the source to build the full system.   I looked and did not find the
source of this minimal compiler--so it is a black box in a way.

In free software it is ideal to build everything from source.   I
wonder how is such a package handled in Guix?   What is the strategy
for bootstrapping?   Thanks


(msg sent to help-guix first but this list may be more appropriate)