gnu: Add ghc-unliftio.

* gnu/packages/haskell.scm (ghc-unliftio): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/haskell.scm

@@ -9371,4 +9371,33 @@ (define-public ghc-microlens-th
 used both from lens and microlens).")
     (license license:bsd-3)))
 
+(define-public ghc-unliftio
+  (package
+    (name "ghc-unliftio")
+    (version "0.2.4.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append
+             "https://hackage.haskell.org/package/unliftio/unliftio-"
+             version
+             ".tar.gz"))
+       (sha256
+        (base32
+         "0vpncmwaq5zb6bziqfns4qdgxmq8ky0rlxna2yngxp170s5zxx9z"))))
+    (build-system haskell-build-system)
+    (arguments `(#:tests? #f)) ; FIXME: hspec-discover not in PATH
+    (inputs
+     `(("ghc-async" ,ghc-async)
+       ("ghc-stm" ,ghc-stm)
+       ("ghc-unliftio-core" ,ghc-unliftio-core)))
+    (native-inputs `(("ghc-hspec" ,ghc-hspec)))
+    (home-page "https://github.com/fpco/unliftio")
+    (synopsis "Provides MonadUnliftIO typecplass for unlifting monads to
+IO (batteries included)")
+    (description "This Haskell package provides the core @code{MonadUnliftIO}
+typeclass, a number of common instances, and a collection of common functions
+working with it.")
+    (license license:expat)))
+
 ;;; haskell.scm ends here