https://bugs.gentoo.org/969390
https://github.com/OpenMathLib/OpenBLAS/issues/5607
https://github.com/OpenMathLib/OpenBLAS/pull/5615

From 874243421298866d116e1e8bdbd7e0ed4e31e4f6 Mon Sep 17 00:00:00 2001
From: Martin Kroeker <martin@ruby.chemie.uni-freiburg.de>
Date: Sun, 18 Jan 2026 19:55:40 +0100
Subject: [PATCH 1/2] Include thread callback replacement hook in
 singlethreaded builds as well

---
 driver/others/CMakeLists.txt | 2 +-
 driver/others/Makefile       | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/driver/others/CMakeLists.txt b/driver/others/CMakeLists.txt
index a07a0baf99..72abdc4ee4 100644
--- a/driver/others/CMakeLists.txt
+++ b/driver/others/CMakeLists.txt
@@ -27,7 +27,6 @@ if (USE_THREAD)
     ${BLAS_SERVER}
     divtable.c # TODO: Makefile has -UDOUBLE
     blas_l1_thread.c
-    blas_server_callback.c
   )
 
   if (NOT NO_AFFINITY)
@@ -42,6 +41,7 @@ set(COMMON_SOURCES
   openblas_env.c
   openblas_get_num_procs.c
   openblas_get_num_threads.c
+  blas_server_callback.c
 )
 
 # these need to have NAME/CNAME set, so use GenerateNamedObjects, but don't use standard name mangling
diff --git a/driver/others/Makefile b/driver/others/Makefile
index 719d617c45..fbd016e6b0 100644
--- a/driver/others/Makefile
+++ b/driver/others/Makefile
@@ -1,12 +1,12 @@
 TOPDIR	= ../..
 include ../../Makefile.system
 
-COMMONOBJS	 = memory.$(SUFFIX) xerbla.$(SUFFIX) c_abs.$(SUFFIX) z_abs.$(SUFFIX) openblas_set_num_threads.$(SUFFIX) openblas_get_num_threads.$(SUFFIX) openblas_get_num_procs.$(SUFFIX) openblas_get_config.$(SUFFIX) openblas_get_parallel.$(SUFFIX) openblas_error_handle.$(SUFFIX) openblas_env.$(SUFFIX)
+COMMONOBJS	 = memory.$(SUFFIX) xerbla.$(SUFFIX) c_abs.$(SUFFIX) z_abs.$(SUFFIX) openblas_set_num_threads.$(SUFFIX) openblas_get_num_threads.$(SUFFIX) openblas_get_num_procs.$(SUFFIX) openblas_get_config.$(SUFFIX) openblas_get_parallel.$(SUFFIX) openblas_error_handle.$(SUFFIX) openblas_env.$(SUFFIX) blas_server_callback.$(SUFFIX)
 
 #COMMONOBJS	+= slamch.$(SUFFIX) slamc3.$(SUFFIX) dlamch.$(SUFFIX)  dlamc3.$(SUFFIX)
 
 ifdef SMP
-COMMONOBJS	+= blas_server.$(SUFFIX) divtable.$(SUFFIX) blasL1thread.$(SUFFIX) blas_server_callback.$(SUFFIX)
+COMMONOBJS	+= blas_server.$(SUFFIX) divtable.$(SUFFIX) blasL1thread.$(SUFFIX)
 ifneq ($(NO_AFFINITY), 1)
 COMMONOBJS	+= init.$(SUFFIX)
 endif

From 566e315f4f064e5c270e4401adfa3942368ba03a Mon Sep 17 00:00:00 2001
From: Martin Kroeker <martin@ruby.chemie.uni-freiburg.de>
Date: Sun, 18 Jan 2026 19:59:49 +0100
Subject: [PATCH 2/2] Make test_post_fork_async depend on LAPACK as it uses
 getrf

---
 utest/CMakeLists.txt | 5 +++++
 utest/Makefile       | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/utest/CMakeLists.txt b/utest/CMakeLists.txt
index c73152d79a..69c8d0a413 100644
--- a/utest/CMakeLists.txt
+++ b/utest/CMakeLists.txt
@@ -101,9 +101,14 @@ if (NOT USE_OPENMP)
 set(OpenBLAS_utest_src
   ${OpenBLAS_utest_src}
   test_fork.c
+  )
+if (NOT NO_LAPACK)
+set(OpenBLAS_utest_src
+  ${OpenBLAS_utest_src}
   test_post_fork_async.c
   )
 endif()
+endif()
 set(OpenBLAS_utest_src
   ${OpenBLAS_utest_src}
   test_post_fork.c
diff --git a/utest/Makefile b/utest/Makefile
index e92fb67dc1..c3bf7e706b 100644
--- a/utest/Makefile
+++ b/utest/Makefile
@@ -45,7 +45,10 @@ endif
 # FIXME TBD if this works on OSX, SunOS, POWER and zarch
 ifeq ($(OSNAME), $(filter $(OSNAME),Linux CYGWIN_NT))
 ifneq ($(USE_OPENMP), 1)
-OBJS += test_fork.o test_post_fork_async.o
+OBJS += test_fork.o
+ifneq ($(NO_LAPACK), 1)
+OBJS += test_post_fork_async.o
+endif
 endif
 OBJS += test_post_fork.o
 endif