From d27b888f132a9b60dd57c876ce452007f1013796 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Mon, 6 Nov 2023 15:03:09 +0100
Subject: [PATCH] Noise simulation is buggy when using the KLU solver. Thus for
 now it is disabled. Use 'option sparse' instead.

---
 src/spicelib/analysis/noisean.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/spicelib/analysis/noisean.c b/src/spicelib/analysis/noisean.c
index 3798a4c1c..9c22da199 100644
--- a/src/spicelib/analysis/noisean.c
+++ b/src/spicelib/analysis/noisean.c
@@ -77,6 +77,14 @@ NOISEan(CKTcircuit* ckt, int restart)
     /* gtri - end - wbk */
 #endif
 
+#ifdef KLU
+    if (ckt->CKTkluMODE) {
+        fprintf(stderr, "Error: Noise simulation is not (yet) supported with 'option KLU'.\n");
+        fprintf(stderr, "    Use 'option sparse' instead.\n");
+        return(E_UNSUPP);
+    }
+#endif
+
     NOISEAN* job = (NOISEAN*)ckt->CKTcurJob;
     GENinstance* inst = CKTfndDev(ckt, job->input);
     bool frequequal = AlmostEqualUlps(job->NstartFreq, job->NstopFreq, 3);