Hi Julien,

On Tue,  1 May 2018 17:44:28 +0200
Julien Lepiller <julien@lepiller.eu> wrote:

> +  %D%/packages/patches/groovy-Add-exceptionutilsgenerator.patch	\

Capital letter?  Ok I guess, just uncommon.

> +              (uri (string-append "https://github.com/apache/groovy/archive/GROOVY_"
> +                                  (string-map (lambda (x) (if (eq? x #\.) #\_ x)) version)
> +                                  ".tar.gz"))

Hmm, is testing using "eq?" safe?  I'd prefer "char=?".  Even more, I'd prefer using (match ...).

> +    (license (list license:gpl2
> +                   license:cddl1.1))))

Does that mean "AND" or "OR"?  Please add a comment.

> diff --git a/gnu/packages/patches/groovy-Add-exceptionutilsgenerator.patch b/gnu/packages/patches/groovy-Add-exceptionutilsgenerator.patch
> new file mode 100644
> index 000000000..3c81f28cf
> --- /dev/null
> +++ b/gnu/packages/patches/groovy-Add-exceptionutilsgenerator.patch
> @@ -0,0 +1,96 @@
> +From 3dbdc68093e90f0ef9b77b70490d8e0b1dcfbf8f Mon Sep 17 00:00:00 2001
> +From: Julien Lepiller <julien@lepiller.eu>
> +Date: Sun, 17 Sep 2017 21:08:45 +0200
> +Subject: [PATCH] Add ExceptionUtilsGenerator.java from previous versions
> +
> +This is replaced by a gradle task, but gradle depends on groovy, so we
> +need so way to generate the file without gradle.

It might make sense to add a comment which version exactly this was copied from.