The hash in this patch is the wrong one, I’ve attached the fixed patch:
Divya Ranjan via Guix-patches via <guix-patches@gnu.org> writes:

> * gnu/packages/fonts.scm (font-spline-sans-mono): New variable.
> ---
>  gnu/packages/fonts.scm | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/gnu/packages/fonts.scm b/gnu/packages/fonts.scm
> index 3c60f5e4a1..58d8a49110 100644
> --- a/gnu/packages/fonts.scm
> +++ b/gnu/packages/fonts.scm
> @@ -3674,6 +3674,31 @@ (define-public font-spline-sans
>  traps, which blossom into view when set at larger sizes.")
>        (license license:silofl1.1))))
>  
> +(define-public font-spline-sans-mono
> +  (let ((commit "b167db03b7d7ae754bf7071c13415e7aeee7d073")
> +        (revision "0"))
> +    (package
> +      (name "font-spline-sans-mono")
> +      (version (git-version "0.0.0" revision commit))
> +      (source
> +       (origin
> +         (method git-fetch)
> +         (uri (git-reference
> +               (url "https://github.com/SorkinType/SplineSansMono")
> +               (commit commit)))
> +         (file-name (git-file-name name version))
> +         (sha256
> +          (base32 "0lrckl39ivklxk3cfd761lsghwdx68yyvcmkrij9s54cp0hvnl63"))))
> +      (build-system font-build-system)
> +      (home-page "https://fonts.google.com/specimen/Spline+Sans+Mono")
> +      (synopsis
> +       "Monospaced Grotesque purpose-built for UI interfaces, and programming")
> +      (description
> +       "Spline Sans Mono is a Monospaced Grotesque purpose-built for UI interfaces,
> +checkout processes, and programming.  Space efficiency is accomplished by condensing
> +traditional grotesque proportions.")
> +      (license license:silofl1.1))))
> +
>  (define-public font-scientifica
>    (package
>      (name "font-scientifica")

-- 
Divya Ranjan,
Philosophy, Mathematics, Libre Software.

PGP Fingerprint: F0B3 1A69 8006 8FB8 096A  2F12 B245 10C6 108C 8D4A