Update comment about ghc9 crashing on initDynLinker

Author: anka-213

ghcide/session-loader/Development/IDE/Session.hs

@@ -527,7 +527,8 @@ emptyHscEnv :: IORef NameCache -> FilePath -> IO HscEnv
 emptyHscEnv nc libDir = do
     env <- runGhc (Just libDir) getSession
 #if !MIN_VERSION_ghc(9,0,0)
-    -- This causes ghc9 to crash
+    -- This causes ghc9 to crash with the error:
+    -- Couldn't find a target code interpreter. Try with -fexternal-interpreter
     initDynLinker env
 #endif
     pure $ setNameCache nc env{ hsc_dflags = (hsc_dflags env){useUnicode = True } }