gnu: Add rust-hex-literal-impl-0.2.

* gnu/packages/crates-io.scm (rust-hex-literal-impl-0.2): New variable.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/crates-io.scm

@@ -3106,6 +3106,30 @@ hexadecimal representation.")
 compile time.")
     (license (list license:asl2.0 license:expat))))
 
+(define-public rust-hex-literal-impl-0.2
+  (package
+    (name "rust-hex-literal-impl")
+    (version "0.2.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "hex-literal-impl" version))
+       (file-name
+        (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "04m6d1k57a9h3hhdgn0vq1hkfwjv9hfkw6q73bqn0my0qw45s286"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:skip-build? #t
+       #:cargo-inputs
+       (("rust-proc-macro-hack" ,rust-proc-macro-hack-0.5))))
+    (home-page "https://github.com/RustCrypto/utils")
+    (synopsis "Internal implementation of the hex-literal crate")
+    (description
+     "Internal implementation of the hex-literal crate.")
+    (license (list license:asl2.0 license:expat))))
+
 (define-public rust-humantime-1.2
   (package
     (name "rust-humantime")