(define-public coq-8.6

  (package

    (inherit coq)

    (name "coq")

    (version "8.6.1")

    (source (origin

              (method url-fetch)

              (uri (string-append "https://github.com/coq/coq/archive/V"

                                  version ".tar.gz"))

              (file-name (string-append name "-" version ".tar.gz"))

              (sha256

               (base32

                "02nm5sn79hrb9fdmkhyclk80jydadf4jcafmr3idwr5h4z56qbms"))))

    ;(native-inputs

    ; `(("ocamlbuild" ,ocaml-build)

    ;   ("hevea" ,hevea)

    ;   ("texlive" ,texlive)))

    ;(inputs

    ; `(("lablgtk" ,lablgtk)

    ;   ("python" ,python-2)

    ;   ("camlp5" ,camlp5)))

    (arguments

     `(#:phases

       (modify-phases %standard-phases

         (replace 'configure

           (lambda* (#:key outputs #:allow-other-keys)

             (let* ((out (assoc-ref outputs "out"))

                    (mandir (string-append out "/share/man"))

                    (browser "icecat -remote \"OpenURL(%s,new-tab)\""))

               (invoke "./configure"

                       "-prefix" out

                       "-mandir" mandir

                       "-browser" browser

                       "-coqide" "opt"))

             #t))

         (replace 'build

           (lambda* (#:key inputs #:allow-other-keys)

             (substitute* "ide/ideutils.ml"

               (("Bytes.unsafe_to_string read_string") "read_string"))

             (invoke "make" "-j" (number->string

                                  (parallel-job-count))

                     "world")

             #t))

         (delete 'check)

         (add-after 'install 'check

           (lambda _

             (with-directory-excursion "test-suite"

               (invoke "make"))

             #t)))))))

(define-public opam2

  (package

    (inherit opam)

    (version "2.0.0")

    (source (origin

              (method url-fetch)

              ;; Use the '-full' version, which includes all the dependencies.

              (uri (string-append

                    "https://github.com/ocaml/opam/releases/download/"

                    version "/opam-full-" version ".tar.gz")

               ;; (string-append "https://github.com/ocaml/opam/archive/"

               ;;                    version ".tar.gz")

               )

              (sha256

               (base32

                "09gdpxiqmyr6z78l85d7pwhiwrycdi2xi1b2mafqr1sk9z5lzbcx"))))))