The latest conjure48 version at my repository is able to build s42, and run the test suites—doc generation is almost there too.
If you have the s42 source tree, you can try it with the following incantations :
$ ln -s conjure/examples/s42/build.scm . $ ln -s conjure/examples/s42/build.exec . $ scheme48 > ,exec ,load "build.exec" > (build-system "s42" "test")
That will run the testsuite. Other goals that can be used instead of ‘test’ are ‘runners’, ‘s42.image’ or ‘doc’. If you take a look at the build script and find it ugly, please keep in mind that this is still alpha code, and that s42 is a rather complex system when it comes to building. This simpler build file for a test C project is closer to what we envision. From here, we’ll be polishing the syntax and interfaces to attain our DSL-for-non-schemers goal.
 There are some tricky issues that you may stumble upon to get there. Please, do not hesitate to contact us at #conjure in Freenode.