texinfo processing

[Catonano]

I already posted this on guix-devel but someone observed tat this is
probably more suited to guile-user

In playing with David's Haunt, I came to the procedure

texi-fragment->stexi

I'd like the <pre> tag that the examples are wrapped in to have the
class="src example" attribute in the resulting html

Because I have a bunch of css rules applying to those classes

I'm suspicious that the texi-fragment->stexi procedure isn't doing the
right thing, so I'd love to inspect its code

I have managed to make guile and Geiser work enough that I can press M-.
and jump to a definition _within the Haunt code base_

But "texi-fragment->stexi" is defined in a texinfo module bundled with Guile

How can I manage to have the guile texinfo code available in my environment
?

I'd like to be able to jump from definition to definition regardless of
project boundaries

Thanks