Test Trac #6054

5 files changed, 31 insertions, 1 deletions

diff --git a/testsuite/tests/polykinds/Makefile b/testsuite/tests/polykinds/Makefile
index 9f3fb669b3..4ac688d458 100644
--- a/testsuite/tests/polykinds/Makefile
+++ b/testsuite/tests/polykinds/Makefile
@@ -9,9 +9,15 @@ T5881:
 	'$(TEST_HC)' $(TEST_HC_OPTS) -c T5881a.hs
 	'$(TEST_HC)' $(TEST_HC_OPTS) -c T5881.hs
 
-# T6025 is like T5881; needs separat compile
+# T6025 is like T5881; needs separate compile
 T6025:
 	$(RM) -f T6025.hi T6025.o T6025a.hi T6025a.o
 	'$(TEST_HC)' $(TEST_HC_OPTS) -c T6025a.hs
 	'$(TEST_HC)' $(TEST_HC_OPTS) -c T6025.hs
 
+# T6054 is like T5881; needs separate compile
+# The second compile fails, and should do so, hence leading "-"
+T6054:
+	$(RM) -f T6054.hi T6054.o T6054a.hi T6054a.o
+	'$(TEST_HC)' $(TEST_HC_OPTS) -c T6054a.hs
+	-'$(TEST_HC)' $(TEST_HC_OPTS) -c T6054.hs
diff --git a/testsuite/tests/polykinds/T6054.hs b/testsuite/tests/polykinds/T6054.hs
new file mode 100644
index 0000000000..f1801ab26c
--- /dev/null
+++ b/testsuite/tests/polykinds/T6054.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE FlexibleContexts, DataKinds #-}
+
+module T6054 where
+
+import T6054a
+
+foo = print (Proxy :: Bar '() a => Proxy a)
diff --git a/testsuite/tests/polykinds/T6054.stderr b/testsuite/tests/polykinds/T6054.stderr
new file mode 100644
index 0000000000..9b190ce4d8
--- /dev/null
+++ b/testsuite/tests/polykinds/T6054.stderr
@@ -0,0 +1,10 @@
+
+T6054.hs:7:14:
+    No instance for (Bar () '() a0)
+      arising from an expression type signature
+    Possible fix: add an instance declaration for (Bar () '() a0)
+    In the first argument of `print', namely
+      `(Proxy :: Bar () a => Proxy a)'
+    In the expression: print (Proxy :: Bar () a => Proxy a)
+    In an equation for `foo':
+        foo = print (Proxy :: Bar () a => Proxy a)
diff --git a/testsuite/tests/polykinds/T6054a.hs b/testsuite/tests/polykinds/T6054a.hs
new file mode 100644
index 0000000000..5b1077f0da
--- /dev/null
+++ b/testsuite/tests/polykinds/T6054a.hs
@@ -0,0 +1,6 @@
+{-# LANGUAGE PolyKinds, FunctionalDependencies, KindSignatures, MultiParamTypeClasses, DataKinds #-}
+
+module T6054a where
+
+class Bar a (p :: Bool) | a -> p
+data Proxy a = Proxy deriving Show
diff --git a/testsuite/tests/polykinds/all.T b/testsuite/tests/polykinds/all.T
index 5f136b16b9..3e026da116 100644
--- a/testsuite/tests/polykinds/all.T
+++ b/testsuite/tests/polykinds/all.T
@@ -43,3 +43,4 @@ test('T6039', normal, compile_fail, [''])
 test('T6021', normal, compile_fail, [''])
 test('T6020a', normal, compile, [''])
 test('T6044', normal, compile, [''])
+test('T6054', normal, run_command, ['$MAKE -s --no-print-directory T6054'])