No Z15 kernel appears to exist for now.

openblas-0.3.8-noz15.patch

@@ -0,0 +1,55 @@
+From 5a6bba3061f19923eb9972378021e6498bf8e5ed Mon Sep 17 00:00:00 2001
+From: Susi Lehtola <susi.lehtola@alumni.helsinki.fi>
+Date: Tue, 11 Feb 2020 15:07:33 +1300
+Subject: [PATCH] Patch out instances of Z15 in dynamic_zarch.c
+
+There does not appear to be a Z15 kernel yet, causing link errors from the code. This patch fixes the issue.
+---
+ driver/others/dynamic_zarch.c | 10 +++++-----
+ 1 file changed, 5 insertions(+), 5 deletions(-)
+
+diff --git a/driver/others/dynamic_zarch.c b/driver/others/dynamic_zarch.c
+index 1206bf870..c7b82e4df 100644
+--- a/driver/others/dynamic_zarch.c
++++ b/driver/others/dynamic_zarch.c
+@@ -3,12 +3,12 @@
+ 
+ extern gotoblas_t gotoblas_Z13;
+ extern gotoblas_t gotoblas_Z14;
+-extern gotoblas_t gotoblas_Z15;
++//extern gotoblas_t gotoblas_Z15;
+ //#if (!defined C_GCC) || (GCC_VERSION >= 60000)
+ //extern gotoblas_t gotoblas_Z14;
+ //#endif
+ 
+-#define NUM_CORETYPES 5
++#define NUM_CORETYPES 4
+ 
+ extern void openblas_warning(int verbose, const char* msg);
+ 
+@@ -16,14 +16,14 @@ static char* corename[] = {
+ 	"unknown",
+ 	"Z13",
+ 	"Z14",
+-	"Z15",
++//	"Z15",
+ 	"ZARCH_GENERIC",
+ };
+ 
+ char* gotoblas_corename(void) {
+ 	if (gotoblas == &gotoblas_Z13)	return corename[1];
+ 	if (gotoblas == &gotoblas_Z14)	return corename[2];
+-	if (gotoblas == &gotoblas_Z15)	return corename[3];
++//	if (gotoblas == &gotoblas_Z15)	return corename[3];
+ //#if (!defined C_GCC) || (GCC_VERSION >= 60000)
+ //	if (gotoblas == &gotoblas_POWER9)	return corename[3];
+ //#endif
+@@ -78,7 +78,7 @@ static gotoblas_t* force_coretype(char* coretype) {
+ 	{
+ 	case  1: return (&gotoblas_Z13);
+ 	case  2: return (&gotoblas_Z14);
+-	case  3: return (&gotoblas_Z15);
++//	case  3: return (&gotoblas_Z15);
+ //#if (!defined C_GCC) || (GCC_VERSION >= 60000)
+ //	case  3: return (&gotoblas_POWER9);
+ //#endif

openblas.spec

@@ -31,6 +31,8 @@ Patch3:         openblas-0.3.7-tests.patch
 
 # https://patch-diff.githubusercontent.com/raw/xianyi/OpenBLAS/pull/2405.patch
 Patch4:         openblas-0.3.8-zarch.patch
+# https://github.com/xianyi/OpenBLAS/pull/2407
+Patch5:         openblas-0.3.8-noz15.patch
 
 BuildRequires:  gcc
 BuildRequires:  gcc-c++
@@ -245,6 +247,7 @@ cd OpenBLAS-%{version}
 %endif
 %patch3 -p1 -b .tests
 %patch4 -p1 -b .zarch
+%patch5 -p1 -b .noz15
 
 # Fix source permissions
 find -name \*.f -exec chmod 644 {} \;