diff --git a/backport-add-strerror-to-error-message.patch b/backport-add-strerror-to-error-message.patch
new file mode 100644
index 0000000000000000000000000000000000000000..6f4602d42ae15b3db71e613832d87c367ad2d3fe
--- /dev/null
+++ b/backport-add-strerror-to-error-message.patch
@@ -0,0 +1,25 @@
+From a4abd7343145d9050f7b37e7c82f8775f98d01f0 Mon Sep 17 00:00:00 2001
+From: Ryan McCullagh <me@ryanmccullagh.com>
+Date: Wed, 10 Jan 2018 19:06:02 -0600
+Subject: [PATCH] add strerror to error message
+
+---
+ src/scan.l | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/scan.l b/src/scan.l
+index 37b37ca..9fd3453 100644
+--- a/src/scan.l
++++ b/src/scan.l
+@@ -1078,7 +1078,7 @@ void set_input_file( char *file )
+ 		yyin = fopen( infilename, "r" );
+ 
+ 		if ( yyin == NULL )
+-			lerr( _( "can't open %s" ), file );
++			lerr( _( "can't open %s: %s" ), file, strerror(errno));
+ 		}
+ 
+ 	else
+-- 
+2.33.0
+
diff --git a/flex.spec b/flex.spec
index 82c1c075a4de741e872d8a1f9c5d296ed7896d38..88d50f637ec439b30273efcb904a434968917db4 100644
--- a/flex.spec
+++ b/flex.spec
@@ -1,6 +1,6 @@
 Name: flex
 Version: 2.6.4
-Release: 5
+Release: 6
 Summary: A fast lexical analyzer generator
 License: BSD
 URL: https://github.com/westes/flex
@@ -17,8 +17,14 @@ Patch0007: scanner-temporarily-protect-against-ccl-overflow-ove.patch
 Patch0008: scanner-prevent-overflow-in-add_action.patch
 Patch0009: 0001-scanner-fix-default-of-yy_top_state.patch
 Patch0010: 0002-scanner-fix-default-of-yy_top_state.patch
+Patch0011: backport-add-strerror-to-error-message.patch
 
 BuildRequires: gcc gcc-c++ gettext help2man m4 bison texinfo automake autoconf
+
+#Ensure that the command: flex ,exists in the compilation environment.
+#Otherwise, compilation fails.
+BuildRequires: flex
+
 Requires: m4
 Requires(post): info
 Requires(preun): info
@@ -105,6 +111,9 @@ fi
 %{_mandir}/man1/*
 
 %changelog
+* Thu Aug 01 2024 zhangruifang <zhangruifang@h-partners.com> - 2.6.4-6
+- backport patch from upstream
+
 * Tue Jul 12 2022 panxiaohe <panxh.life@foxmail.com> - 2.6.4-5
 - enable check test suite
 - delete duplicate package files: NEWS,README.md