The `make regression` line was failing because the expression was
downloading a core-system-only, no-libraries source tarball. I
switched to using fetchFromGitHub, which downloads the full source
code -- the core system as well as the "community books",
i.e. libraries -- but the libraries unfortunately do not build yet
because they have more dependencies than the core system, and they
also run into some impurity problems during the build process.
This commit changes the ACL2 package so that at least the user will
obtain the latest version of the core system, even though they won't
get the community books. In a later commit I hope to fix this; it
will require either changes to ACL2 itself, or a patch to be applied
to ACL2 in nixpkgs.
ACL2 7.4 has no trouble building on the current version of SBCL in
nixpkgs, so I let it do so instead of using the ancient SBCL version
1.2.0 from 2014.
I also added myself as a maintainer to this package, since I'm an
active contributor to the ACL2 project and am interested in seeing it
working on Nix.
0094ca20cc