Hi,

I'm currently experimenting with modifications of the asdf-build-system
to see if it can be simplified.

I tried adding a profile hook that creates the ASDF configuration files
in 'etc/common-lisp/' based on the lisp packages that are present in the
manifest. When using 'guix environment -C --ad-hoc sbcl-lift' for
example, the configuration files are created and contain the right paths
for the sources and compiled files of sbcl-lift, which allows sbcl to
find and load the library.

However, when building a package depending on sbcl-lift, for example
with 'guix build sbcl-trivial-backtrace', sbcl fails to find sbcl-lift.
So it seems that the build environment created by 'guix build' doesn't
run profile hooks, and the ASDF configuration files are missing.

Is there a way to generate files and add them to the environment created
by 'guix build' as it can be done with profile hooks?