Catch type-checker exceptions when splicingwip/T20179

In GHC.Tc.Gen.Splice.tcTopSpliceExpr we were forgetting to
catch exceptions. As a result we missed the kind error
in the unsolved constraints.

This patch has an easy fix, which cures #20179

3 files changed, 18 insertions, 0 deletions

diff --git a/testsuite/tests/th/T20179.hs b/testsuite/tests/th/T20179.hs
new file mode 100644
index 0000000000..a01f573979
--- /dev/null
+++ b/testsuite/tests/th/T20179.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Bug where
+
+$(let slurmp :: [Maybe]
+      slurmp = []
+
+   in pure [])
diff --git a/testsuite/tests/th/T20179.stderr b/testsuite/tests/th/T20179.stderr
new file mode 100644
index 0000000000..28eb54d698
--- /dev/null
+++ b/testsuite/tests/th/T20179.stderr
@@ -0,0 +1,10 @@
+
+T20179.hs:4:18: error:
+    • Expecting one more argument to ‘Maybe’
+      Expected a type, but ‘Maybe’ has kind ‘* -> *’
+    • In the type signature: slurmp :: [Maybe]
+      In the expression:
+        let
+          slurmp :: [Maybe]
+          slurmp = []
+        in pure []
diff --git a/testsuite/tests/th/all.T b/testsuite/tests/th/all.T
index a19ad09ec9..77ed446d95 100644
--- a/testsuite/tests/th/all.T
+++ b/testsuite/tests/th/all.T
@@ -531,3 +531,4 @@ test('T19470', only_ways(['ghci']), ghci_script, ['T19470.script'])
 test('T19737', normal, compile, [''])
 test('T19759', normal, compile, [''])
 test('T20060', normal, compile, [''])
+test('T20179', normal, compile_fail, [''])