gnu: ganeti: Adjust to GHC 8.10 / Stackage 18.10.

* gnu/packages/patches/ganeti-haskell-compat.patch: New file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/virtualization.scm (ganeti)[source](patches): Add it.
[arguments]: Add phase patch-version-constraints.

gnu/local.mk

@@ -1064,6 +1064,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/fxdiv-system-libraries.patch		\
   %D%/packages/patches/gajim-honour-GAJIM_PLUGIN_PATH.patch	\
   %D%/packages/patches/ganeti-disable-version-symlinks.patch	\
+  %D%/packages/patches/ganeti-haskell-compat.patch		\
   %D%/packages/patches/ganeti-haskell-pythondir.patch		\
   %D%/packages/patches/ganeti-preserve-PYTHONPATH.patch		\
   %D%/packages/patches/ganeti-shepherd-master-failover.patch	\

gnu/packages/patches/ganeti-haskell-compat.patch

@@ -0,0 +1,18 @@
+Adjust to type change of TupE in Template Haskell 2.16.
+
+diff --git a/src/Ganeti/THH/Types.hs b/src/Ganeti/THH/Types.hs
+--- a/src/Ganeti/THH/Types.hs
++++ b/src/Ganeti/THH/Types.hs
+@@ -123,4 +123,11 @@ curryN n = do
+   f <- newName "f"
+   ps <- replicateM n (newName "x")
+   return $ LamE (VarP f : map VarP ps)
+-             (AppE (VarE f) (TupE $ map VarE ps))
++             (AppE (VarE f) (nonUnaryTupE $ map VarE ps))
++  where
++    nonUnaryTupE :: [Exp] -> Exp
++    nonUnaryTupE es = TupE $
++#if MIN_VERSION_template_haskell(2,16,0)
++                            map Just
++#endif
++                            es

gnu/packages/virtualization.scm

@@ -524,6 +524,7 @@ firmware blobs.  You can
               (file-name (git-file-name name version))
               (patches (search-patches "ganeti-shepherd-support.patch"
                                        "ganeti-shepherd-master-failover.patch"
+                                       "ganeti-haskell-compat.patch"
                                        "ganeti-haskell-pythondir.patch"
                                        "ganeti-disable-version-symlinks.patch"
                                        "ganeti-preserve-PYTHONPATH.patch"))))
@@ -573,6 +574,14 @@ firmware blobs.  You can
                             ,(system->qemu-target (%current-system))))
        #:phases
        (modify-phases %standard-phases
+         (add-after 'unpack 'patch-version-constraints
+           (lambda _
+             ;; Loosen version constraints for compatibility with Stackage 18.10.
+             (substitute* "cabal/ganeti.template.cabal"
+               (("(.*base64-bytestring.*) < 1\\.1" _ match)
+                (string-append match " < 1.2"))
+               (("(.*QuickCheck.*) < 2\\.14" _ match)
+                (string-append match " < 2.15")))))
          (add-after 'unpack 'create-vcs-version
            (lambda _
              ;; If we are building from a git checkout, we need to create a