This is what we previously did with ‘my-hello’. With the Scheme basics
we’ve covered, we are now able to explain the leading chunks. As stated in
guix package --help:
-f, --install-from-file=FILE install the package that the code within FILE evaluates to
Thus the last expression must return a package, which is the case in our earlier example.
The use-modules expression tells which of the modules we need in the
file. Modules are a collection of values and procedures. They are commonly
called “libraries” or “packages” in other programming languages.