. this.
(inferior-packages): New procedure; force the promise.
(%inferior-package-table, lookup-inferior-packages): New procedures.
* tests/inferior.scm ("lookup-inferior-packages")
("lookup-inferior-packages and eq?-ness"): New tests.
* guix/inferior.scm (read-inferior-response)
(send-inferior-request): New procedures.
(inferior-eval): Rewrite in terms of these.
(proxy, inferior-package-derivation, inferior-package->derivation)
(package-compiler): New procedures.
* tests/inferior.scm ("inferior-package-derivation"): New test.