Subject: Re: [bug#34466] [PATCH] gnu: Add coq-equations.

From: Julien Lepiller <[email-masked]>
Date: Wed, 13 Feb 2019 12:04:48 +0100

Le 2019-02-13 11:40, Dan Frumin a écrit :
> ---
>  gnu/packages/coq.scm | 40 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/gnu/packages/coq.scm b/gnu/packages/coq.scm
> index fa02f85cd..494c3404b 100644
> --- a/gnu/packages/coq.scm
> +++ b/gnu/packages/coq.scm
> @@ -500,3 +500,43 @@ work on a decision procedure for the equational
> theory of an extension of the
>  sigma-calculus by Abadi et al.  The library is completely written in 
> Coq and
>  uses Ltac to synthesize the substitution operation.")
>        (license license:bsd-3))))

Hi Dan, thanks for this patch! I have some comments below to help 
improve the
quality of future patches, as well as two questions you need to answer 
before
I can push that patch.

> +
> +(define-public coq-equations
> +  (package
> +    (name "coq-equations")
> +    (synopsis "Equations - a function definition plugin")

Could you put this just before the description field, so this package 
definition
looks more like the rest of guix? A better synopsis would be "Function 
definiton
plugin for coq" I think.

> +    (version "1.2-beta")

Why a beta version? We try to stick to stable releases in Guix. Please 
add a
comment explaining the reason.

> +    (source (origin
> +              (method url-fetch)
> +              (uri (string-append
> +                    
> "https://github.com/mattam82/Coq-Equations/archive/v"
> +                    version "-8.8.tar.gz"))
> +              (file-name (string-append name "-v" version 
> "8.8.tar.gz"))

We cannot use auto-generated tarballs from github, because we found that
they sometimes get regenerated in an unreproducible way, so it breaks 
the
checksum test. You can use this instead:

(method git-fetch)
(uri (git-reference
        (url "https://githu.com/mattam82/Coq-Equations.git")
        (commit (string-append "v" version "-8.8"))))

and update the sha256 accordingly. As an added bonus, this means that we
can always fetch from the software heritage in case the repo disappears
one day :)

> +              (sha256
> +               (base32
> "1j7yarhddk2c2l4b6h8g5n0xz5vfy1bqmgh832g01di5gjwshy3f"))))
> +    (build-system gnu-build-system)
> +    (native-inputs
> +     `(("findlib" ,ocaml)

ocaml doesn't provide findlib directly, ocaml-findlib does. What do you
want to do here?

> +       ("coq"     ,coq)
> +       ("camlp5"  ,camlp5)))
> +    (arguments
> +     `(#:test-target "test-suite"
> +       #:phases
> +       (modify-phases %standard-phases
> +         (replace 'configure
> +           (lambda* (#:key outputs #:allow-other-keys)
> +             (invoke "coq_makefile" "-f" "_CoqProject" "-o" 
> "Makefile")))
> +         (replace 'install
> +           (lambda* (#:key outputs #:allow-other-keys)
> +             (setenv "COQLIB" (string-append (assoc-ref outputs
> "out") "/lib/coq/"))
> +             (invoke "make"
> +                     (string-append "COQLIB=" (assoc-ref outputs 
> "out")
> +                                    "/lib/coq/")
> +                     "install"))))))

Please make sure that these two phases both return #t.

> +    (description "Equations provides a notation for writing programs
> +by dependent pattern-matching and (well-founded) recursion in Coq. It
> +compiles everything down to eliminators for inductive types, equality
> +and accessibility, providing a definitional extension to the Coq
> +kernel.")

Please make sure that each sentence is separated by two spaces.
`guix lint coq-equations` should be able to tell you about it.

> +    (home-page "https://mattam82.github.io/Coq-Equations/")
> +    (license license:lgpl2.1)))

Thanks again! I really only need an answer for the beta version and
ocaml/findlib questions. I can take care of the rest, but I would
appreciate it if you could do it yourself ;)