Ryan Prior via Guix-patches via <guix-patches@gnu.org> writes:

> * gnu/packages/ruby.scm (ruby): Add 3.0.
> ---
>  gnu/packages/ruby.scm | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/gnu/packages/ruby.scm b/gnu/packages/ruby.scm
> index 1befecfa12..971b2b2d77 100644
> --- a/gnu/packages/ruby.scm
> +++ b/gnu/packages/ruby.scm
> @@ -187,6 +187,20 @@ a focus on simplicity and productivity.")
>      (native-inputs
>       `(("autoconf" ,autoconf)))))
>  
> +(define-public ruby-3.0
> +  (package
> +    (inherit ruby-2.7)
> +    (version "3.0.0")
> +    (source
> +     (origin
> +       (method url-fetch)
> +       (uri (string-append "http://cache.ruby-lang.org/pub/ruby/"
> +                           (version-major+minor version)
> +                           "/ruby-" version ".tar.xz"))
> +       (sha256
> +        (base32
> +         "1cbcixwnr0y8q0lg67wjgplp06kjd6p6hjjh680csv3v0bpsxgv8"))))))
> +
>  (define-public ruby-2.5
>    (package
>      (inherit ruby)

Thanks, I've tweaked the commit message, and pushed to master as
03c51c04430405fe405a3640e6a4d1d248b702fc.