gnu: Add rust-shadow-rs-0.8.

* gnu/packages/crates-io.scm (rust-shadow-rs-0.8): New variable.
(rust-shadow-rs-0.6): Inherit from above.

gnu/packages/crates-io.scm

@@ -49392,8 +49392,35 @@ functions core functionality.")
 picking compatible shaders.")
     (license license:expat)))
 
+(define-public rust-shadow-rs-0.8
+  (package
+    (name "rust-shadow-rs")
+    (version "0.8.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "shadow-rs" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32 "0iy4f6yzag52qr93hjhm2l8crxhjblr91nffbdd8zzw0xchfjdc9"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:skip-build? #t
+       #:cargo-inputs
+       (("rust-chrono" ,rust-chrono-0.4)
+        ("rust-git2" ,rust-git2-0.13)
+        ("rust-is-debug" ,rust-is-debug-1))))
+    (home-page "https://github.com/baoyachi/shadow-rs")
+    (synopsis "Recall properties of the build process at run time")
+    (description
+     "@code{shadow-rs} allows you to recall properties of the build process
+and environment at run time.  You can use this tool to check in production
+exactly where a binary came from and how it was built.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-shadow-rs-0.6
   (package
+    (inherit rust-shadow-rs-0.8)
     (name "rust-shadow-rs")
     (version "0.6.2")
     (source
@@ -49404,19 +49431,11 @@ picking compatible shaders.")
         (string-append name "-" version ".tar.gz"))
        (sha256
         (base32 "0sps996yhchz43zfk9zysjpirz638s1hbhspp998bk6v9l6k7j10"))))
-    (build-system cargo-build-system)
     (arguments
      `(#:skip-build? #t
        #:cargo-inputs
        (("rust-chrono" ,rust-chrono-0.4)
-        ("rust-git2" ,rust-git2-0.13))))
+        ("rust-git2" ,rust-git2-0.13))))))
-    (home-page "https://github.com/baoyachi/shadow-rs")
-    (synopsis "Recall properties of the build process at run time")
-    (description
-     "@code{shadow-rs} allows you to recall properties of the build process
-and environment at run time.  You can use this tool to check in production
-exactly where a binary came from and how it was built.")
-    (license (list license:expat license:asl2.0))))
 
 (define-public rust-shadow-rs-0.5
   (package