Error message wibbles due to reordering constraints (the DPH problem)

testsuite/tests/indexed-types/should_compile/T3017.stderr

 TYPE SIGNATURES
     emptyL :: forall a. ListColl a
     test2 :: forall c t t1.
-             (Num t1, Num t, Coll c, Elem c ~ (t, t1)) =>
+             (Num t, Num t1, Coll c, Elem c ~ (t, t1)) =>
              c -> c
 TYPE CONSTRUCTORS
   data ListColl a

testsuite/tests/indexed-types/should_fail/NoMatchErr.stderr

 
-NoMatchErr.hs:20:5:
-    Could not deduce (Memo d ~ Memo d0)
+NoMatchErr.hs:20:12:
+    Could not deduce (Memo d0 ~ Memo d)
     from the context (Fun d)
       bound by the type signature for f :: Fun d => Memo d a -> Memo d a
       at NoMatchErr.hs:20:1-15
     NB: `Memo' is a type function, and may not be injective
     Expected type: Memo d a
       Actual type: Memo d0 a
-    Expected type: Memo d a -> Memo d a
-      Actual type: Memo d0 a -> Memo d0 a
+    Expected type: Memo d a -> d0 -> a
+      Actual type: Memo d0 a -> d0 -> a
+    In the second argument of `(.)', namely `appl'
     In the expression: abst . appl
-    In an equation for `f': f = abst . appl

testsuite/tests/indexed-types/should_fail/T2544.stderr

 
-T2544.hs:15:12:
-    Could not deduce (IxMap l ~ IxMap i0)
+T2544.hs:15:18:
+    Could not deduce (IxMap i0 ~ IxMap l)
     from the context (Ix l, Ix r)
       bound by the instance declaration at T2544.hs:13:10-37
     NB: `IxMap' is a type function, and may not be injective
-    Expected type: IxMap (l :|: r) [Int]
-      Actual type: BiApp (IxMap i0) (IxMap r) [Int]
-    In the return type of a call of `BiApp'
+    Expected type: IxMap l [Int]
+      Actual type: IxMap i0 [Int]
+    In the first argument of `BiApp', namely `empty'
     In the expression: BiApp empty empty
     In an equation for `empty': empty = BiApp empty empty
 

testsuite/tests/indexed-types/should_fail/T2627b.stderr

 
 T2627b.hs:20:24:
     Occurs check: cannot construct the infinite type:
-      b0 = Dual (Dual b0)
+      a0 = Dual (Dual a0)
     In the expression: conn undefined undefined
     In an equation for `conn':
         conn (Rd k) (Wr a r) = conn undefined undefined

testsuite/tests/indexed-types/should_fail/T4099.stderr

 
 T4099.hs:11:14:
-    Couldn't match type `T a0' with `T b'
+    Couldn't match type `T b' with `T a0'
     NB: `T' is a type function, and may not be injective
     In the first argument of `foo', namely `x'
     In the expression: foo x