(let ((init
        '("apt-get update && apt-get install -y git ca-certificates gcc make libffi-dev"
          "git clone https://github.com/ashinn/chibi-scheme.git --depth=1 || true"
          "make -j8 -C chibi-scheme"
          "make -j8 -C chibi-scheme install"
          "snow-chibi install retropikzel.compile-r7rs"))
      (tap
        (lambda (scheme)
          `(,(string-append "snow-chibi install --impls=" scheme " srfi.64")
            ,(string-append "snow-chibi install --impls=" scheme " retropikzel.tap")
            ,(string-append "COMPILE_R7RS="
                           scheme
                           " compile-r7rs -o tap-test-program retropikzel/tap/test.scm")
            "./tap-test-program"))))

  `((makings ,@(map (lambda (scheme)
                      `((name ,scheme)
                        (image ,(string-append "schemers/" scheme ":head"))
                        (stages
                          (init ,@init)
                          (tap ,@(tap scheme)))))
                    '("chibi" "sagittarius")))))