gnu: rust-glium: Add 0.31.0.

* gnu/packages/crates-io.scm (rust-glium-0.31): New variable.
(rust-glium-0.25): Inherit from it.

gnu/packages/crates-io.scm

@@ -25506,8 +25506,42 @@ graphics.")
 graphics.")
     (license (list license:expat license:asl2.0))))
 
+(define-public rust-glium-0.31
+  (package
+    (name "rust-glium")
+    (version "0.31.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "glium" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "06cfsq3mgjlq3bnxv7jh5bb5is7040xyvf8cf1x45vnq8fdz1d0a"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:skip-build? #true              ;XXX circular dependencies
+       #:cargo-inputs
+       (("rust-backtrace" ,rust-backtrace-0.3)
+        ("rust-fnv" ,rust-fnv-1)
+        ("rust-glutin" ,rust-glutin-0.28)
+        ("rust-lazy-static" ,rust-lazy-static-1)
+        ("rust-memoffset" ,rust-memoffset-0.6)
+        ("rust-smallvec" ,rust-smallvec-1)
+        ("rust-takeable-option" ,rust-takeable-option-0.5))
+       #:cargo-development-inputs
+       (("rust-gl-generator" ,rust-gl-generator-0.14))))
+    (home-page "https://github.com/glium/glium")
+    (synopsis "OpenGL wrapper")
+    (description
+     "Glium is an intermediate layer between OpenGL and your application.  You
+still need to manually handle the graphics pipeline, but without having to use
+OpenGL's old and error-prone API.")
+    (license license:asl2.0)))
+
 (define-public rust-glium-0.25
   (package
+    (inherit rust-glium-0.31)
     (name "rust-glium")
     (version "0.25.1")
     (source
@@ -25519,7 +25553,6 @@ graphics.")
        (sha256
         (base32
          "0mhjly07x10lxg802ppg16wbxddhh4fdnlg10i99qwpfamvqhzbd"))))
-    (build-system cargo-build-system)
     (arguments
      `(#:cargo-inputs
        (("rust-backtrace" ,rust-backtrace-0.3)
@@ -25534,15 +25567,7 @@ graphics.")
         ("rust-gl-generator" ,rust-gl-generator-0.11)
         ("rust-image" ,rust-image-0.21)
         ("rust-obj" ,rust-obj-0.9)
-        ("rust-rand" ,rust-rand-0.6))))
+        ("rust-rand" ,rust-rand-0.6))))))
-    (home-page "https://github.com/glium/glium")
-    (synopsis
-     "OpenGL wrapper")
-    (description
-     "Glium is an intermediate layer between OpenGL and your application.  You
-still need to manually handle the graphics pipeline, but without having to use
-OpenGL's old and error-prone API.")
-    (license license:asl2.0)))
 
 (define-public rust-glob-0.3
   (package