diff --git a/flatbuffers.spec b/flatbuffers.spec
index 97d587f24c62a839f7ef6781e388b8fbdb7429d2..40722af1d11e630a94e8ba8bc8aabb1cbcb6811e 100644
--- a/flatbuffers.spec
+++ b/flatbuffers.spec
@@ -5,7 +5,7 @@
 %endif
 Name:                flatbuffers
 Version:             2.0.0
-Release:             5
+Release:             6
 Summary:             Memory efficient serialization library
 License:             Apache-2.0
 URL:                 https://github.com/google/flatbuffers
@@ -18,6 +18,7 @@ Patch1:              0002-typo-fixes-in-comments.patch
 Patch2:              0003-Changes-to-support-binary-schema-file-loading-and-pa.patch
 Patch3:              0004-output-errors-instead-of-stdout.patch
 Patch4:              0005-fix-undefined-behaviour.patch
+Patch5:              test-fix-undefined-order-of-functio-parameters.-6946.patch
 
 BuildRequires:       gcc-c++ cmake >= 2.8.9
 Provides:            bundled(grpc)
@@ -94,6 +95,9 @@ make test
 %{python3_sitelib}/
 
 %changelog
+* Thu Jul 20 2023 chenchen <chen_aka_jan@163.com> - 2.0.0-6
+- fix build error due to gcc upgrade to 12
+
 * Tue Nov 22 2022 Bin Hu <hubin73@huawei.com> - 2.0.0-5
 - add python subpackage for tensorflow 2.10 build
 
diff --git a/test-fix-undefined-order-of-functio-parameters.-6946.patch b/test-fix-undefined-order-of-functio-parameters.-6946.patch
new file mode 100644
index 0000000000000000000000000000000000000000..82a61cd5ab5ed2023ff9d41d834bd60aeb87c8ed
--- /dev/null
+++ b/test-fix-undefined-order-of-functio-parameters.-6946.patch
@@ -0,0 +1,62 @@
+From 85b4effac69202fb360db16ffd0354ef76baa321 Mon Sep 17 00:00:00 2001
+From: Sergei Trofimovich <slyich@gmail.com>
+Date: Mon, 22 Nov 2021 20:14:31 +0000
+Subject: [PATCH] test: fix undefined order of functio parameters. (#6946)
+
+Detected instability when built `flatbuffers-2.0.0` on `gcc-12`:
+
+    [ 75%] Building CXX object CMakeFiles/flattests.dir/tests/test_builder.cpp.o
+    .../c++/12.0.0/bits/shared_ptr_base.h:397:45: error: 'size' may be used uninitialized [-Werror=maybe-uninitialized]
+      397 |       explicit _Sp_ebo_helper(_Tp&& __tp) : _M_tp(std::move(__tp)) { }
+          |                                             ^~~~~~~~~~~~~~~~~~~~~~
+    In file included from flatbuffers/tests/test_builder.cpp:1:
+    flatbuffers/tests/test_builder.h: In function 'void builder_move_assign_after_releaseraw_test(Builder) [with Builder = flatbuffers::FlatBufferBuilder]':
+    flatbuffers/tests/test_builder.h:63:10: note: 'size' was declared here
+       63 |   size_t size, offset;
+          |          ^~~~
+    ...
+    In file included from flatbuffers/tests/test_builder.cpp:1:
+    flatbuffers/tests/test_builder.h: In function 'void builder_move_assign_after_releaseraw_test(Builder) [with Builder = GrpcLikeMessageBuilder]':
+    flatbuffers/tests/test_builder.h:63:10: note: 'size' was declared here
+       63 |   size_t size, offset;
+          |          ^~~~
+    cc1plus: all warnings being treated as errors
+
+Here is the relevant bit of test:
+
+    template<class Builder>
+    void builder_move_assign_after_releaseraw_test(Builder b1) {
+      auto root_offset1 = populate1(b1);
+      b1.Finish(root_offset1);
+      size_t size, offset;
+      std::shared_ptr<uint8_t> raw(
+          b1.ReleaseRaw(size, offset), [size](uint8_t *ptr) {
+            flatbuffers::DefaultAllocator::dealloc(ptr, size);
+          });
+
+Note how `b1.ReleaseRaw(size, offset)` is expected to populate `size`
+and `[size](uint8_t *ptr) {` captures the result. But both are parameters
+to the same function call and thus evaluation order is unspecified.
+---
+ tests/test_builder.h | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/tests/test_builder.h b/tests/test_builder.h
+index 6d97ac00..75338b04 100644
+--- a/tests/test_builder.h
++++ b/tests/test_builder.h
+@@ -61,8 +61,10 @@ void builder_move_assign_after_releaseraw_test(Builder b1) {
+   auto root_offset1 = populate1(b1);
+   b1.Finish(root_offset1);
+   size_t size, offset;
++
++  uint8_t *rr = b1.ReleaseRaw(size, offset);
+   std::shared_ptr<uint8_t> raw(
+-      b1.ReleaseRaw(size, offset), [size](uint8_t *ptr) {
++      rr, [size](uint8_t *ptr) {
+         flatbuffers::DefaultAllocator::dealloc(ptr, size);
+       });
+   Builder src;
+-- 
+2.39.1
+