The QuickCheck library swapped the order of the arguments of the 'cover'
function in version 2.12.  Version 0.3.4 of the Diff library still uses
the old argument order.  Swapping the argument order makes Diff work
with newer versions of QuickCheck.

See <https://github.com/commercialhaskell/stackage/issues/4289> for the
upstream bug report.

diff -ruN a/test/Test.hs b/test/Test.hs
--- a/test/Test.hs	2016-04-23 01:21:45.000000000 -0400
+++ b/test/Test.hs	2019-11-01 19:13:04.590770903 -0400
@@ -134,7 +134,7 @@
 prop_ppDiffR (DiffInput le ri) =
     let haskDiff=ppDiff $ getGroupedDiff le ri
         utilDiff= unsafePerformIO (runDiff (unlines le) (unlines ri))
-    in  cover (haskDiff == utilDiff) 90 "exact match" $
+    in  cover 90 (haskDiff == utilDiff) "exact match" $
                 classify (haskDiff == utilDiff) "exact match"
                         (div ((length haskDiff)*100) (length utilDiff) < 110) -- less than 10% bigger
     where
 right'></td></tr></table>
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<div class='path'>path: <a href='/guix/log/?id=832f577734d1a8f77c599972f249db53bdc1b356'>root</a>/<a href='/guix/log/tests?id=832f577734d1a8f77c599972f249db53bdc1b356'>tests</a>/<a href='/guix/log/tests/upstream.scm?id=832f577734d1a8f77c599972f249db53bdc1b356'>upstream.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/upstream.scm?id=832f577734d1a8f77c599972f249db53bdc1b356&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-01-05 21:17:58 +0100'>2022-01-05</span></td><td><a href='/guix/commit/tests/upstream.scm?id=6226df77ee7448ba4eae05c14aa2ba9721f28bb4'>tests: Add failing tests for changed-inputs on new style inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>* tests/upstream.scm ("changed-inputs returns changes to plain input list",
"changed-inputs returns changes to all plain input lists"): New tests.
</span></span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-01-05 21:17:54 +0100'>2022-01-05</span></td><td><a href='/guix/commit/tests/upstream.scm?id=a6bf1c108ef3b0d63d6d6070b90093bc8f434734'>tests: Add tests for changed-inputs on old-style inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>All these tests pass, because they only test the old-style input alists with
labels.

* tests/upstream.scm ("changed-inputs returns no changes",
"changed-inputs returns changes to labelled input list",
"changed-inputs returns changes to all labelled input lists"): New tests.
</span></span></td><td>Ricardo Wurmus</td></tr>