Explicit migration timeline for loopy SC solving

This patch updates the warning message introduced in commit
9fb4ca89bff9873e5f6a6849fa22a349c94deaae to specify an explicit
migration timeline: GHC will no longer support this constraint solving
mechanism starting from GHC 9.10.

Fixes #22912

8 files changed, 9 insertions, 9 deletions

diff --git a/compiler/GHC/Tc/Errors/Ppr.hs b/compiler/GHC/Tc/Errors/Ppr.hs
index 017b29425c..a9b9718433 100644
--- a/compiler/GHC/Tc/Errors/Ppr.hs
+++ b/compiler/GHC/Tc/Errors/Ppr.hs
@@ -1321,7 +1321,7 @@ instance Diagnostic TcRnMessage where
                  , nest 2 $ pprCtOrigin (ctLocOrigin wtd_loc) <> comma
                  , text "in a way that might turn out to loop at runtime." ]
         warning
-          = vcat [ text "Future versions of GHC will turn this warning into an error." ]
+          = vcat [ text "Starting from GHC 9.10, this warning will turn into an error." ]
         user_manual =
           vcat [ text "See the user manual, § Undecidable instances and loopy superclasses." ]
 
diff --git a/testsuite/tests/typecheck/should_compile/T20666b.stderr b/testsuite/tests/typecheck/should_compile/T20666b.stderr
index 322c6850ea..59445bcf93 100644
--- a/testsuite/tests/typecheck/should_compile/T20666b.stderr
+++ b/testsuite/tests/typecheck/should_compile/T20666b.stderr
@@ -3,7 +3,7 @@ T20666b.hs:11:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
     I am solving the constraint ‘Eq (F [a])’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Eq (F [a])’ to the instance context,
diff --git a/testsuite/tests/typecheck/should_compile/T22891.stderr b/testsuite/tests/typecheck/should_compile/T22891.stderr
index a0bdc1649b..4078683249 100644
--- a/testsuite/tests/typecheck/should_compile/T22891.stderr
+++ b/testsuite/tests/typecheck/should_compile/T22891.stderr
@@ -3,7 +3,7 @@ T22891.hs:9:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
     I am solving the constraint ‘Foo f’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Foo f’ to the instance context,
diff --git a/testsuite/tests/typecheck/should_compile/T22912.stderr b/testsuite/tests/typecheck/should_compile/T22912.stderr
index b53614baff..852a1b6896 100644
--- a/testsuite/tests/typecheck/should_compile/T22912.stderr
+++ b/testsuite/tests/typecheck/should_compile/T22912.stderr
@@ -4,7 +4,7 @@ T22912.hs:17:16: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
       arising from the head of a quantified constraint
       arising from a use of ‘go’,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Implies
diff --git a/testsuite/tests/typecheck/should_fail/T20666.stderr b/testsuite/tests/typecheck/should_fail/T20666.stderr
index 46d0fafcc4..63a0d11c07 100644
--- a/testsuite/tests/typecheck/should_fail/T20666.stderr
+++ b/testsuite/tests/typecheck/should_fail/T20666.stderr
@@ -3,7 +3,7 @@ T20666.hs:13:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
     I am solving the constraint ‘Show (T c)’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Show (T c)’ to the instance context,
@@ -13,7 +13,7 @@ T20666.hs:17:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
     I am solving the constraint ‘Show (T c)’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Show (T c)’ to the instance context,
diff --git a/testsuite/tests/typecheck/should_fail/T20666a.stderr b/testsuite/tests/typecheck/should_fail/T20666a.stderr
index bed585dcd2..c4b3022949 100644
--- a/testsuite/tests/typecheck/should_fail/T20666a.stderr
+++ b/testsuite/tests/typecheck/should_fail/T20666a.stderr
@@ -3,7 +3,7 @@ T20666a.hs:11:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
     I am solving the constraint ‘Eq (F [a])’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Eq (F [a])’ to the instance context,
diff --git a/testsuite/tests/typecheck/should_fail/T6161.stderr b/testsuite/tests/typecheck/should_fail/T6161.stderr
index c1daab09df..f9a9a9e1e1 100644
--- a/testsuite/tests/typecheck/should_fail/T6161.stderr
+++ b/testsuite/tests/typecheck/should_fail/T6161.stderr
@@ -3,7 +3,7 @@ T6161.hs:19:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault)]
     I am solving the constraint ‘Super (Fam a)’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Super (Fam a)’ to the instance context,
diff --git a/testsuite/tests/typecheck/should_fail/tcfail223.stderr b/testsuite/tests/typecheck/should_fail/tcfail223.stderr
index 8201c8839f..2ccfd00dda 100644
--- a/testsuite/tests/typecheck/should_fail/tcfail223.stderr
+++ b/testsuite/tests/typecheck/should_fail/tcfail223.stderr
@@ -3,7 +3,7 @@ tcfail223.hs:10:10: warning: [GHC-36038] [-Wloopy-superclass-solve (in -Wdefault
     I am solving the constraint ‘Class1 a’,
       arising from the superclasses of an instance declaration,
     in a way that might turn out to loop at runtime.
-    Future versions of GHC will turn this warning into an error.
+    Starting from GHC 9.10, this warning will turn into an error.
     See the user manual, § Undecidable instances and loopy superclasses.
     Suggested fix:
       Add the constraint ‘Class1 a’ to the instance context,