diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_dualstack.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_dualstack.h
--- contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_dualstack.h	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_dualstack.h	2022-03-19 15:07:57.455415829 +0100
@@ -1,4 +1,4 @@
 #include "test_configs/opt_dualstack.h"
 
 #undef LWIP_TCP
-#define LWIP_TCP 0
\ No newline at end of file
+#define LWIP_TCP 0
diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv4only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv4only.h
--- contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv4only.h	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv4only.h	2022-03-19 15:08:27.446964821 +0100
@@ -1,4 +1,4 @@
 #include "test_configs/opt_ipv4only.h"
 
 #undef LWIP_TCP
-#define LWIP_TCP 0
\ No newline at end of file
+#define LWIP_TCP 0
diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv6only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv6only.h
--- contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv6only.h	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv6only.h	2022-03-19 15:08:36.622826844 +0100
@@ -1,4 +1,4 @@
 #include "test_configs/opt_ipv6only.h"
 
 #undef LWIP_TCP
-#define LWIP_TCP 0
\ No newline at end of file
+#define LWIP_TCP 0
diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_dualstack.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_dualstack.h
--- contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_dualstack.h	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_dualstack.h	2022-03-19 15:08:43.974716296 +0100
@@ -1,4 +1,4 @@
 #include "test_configs/opt_dualstack.h"
 
 #undef LWIP_UDP
-#define LWIP_UDP 0
\ No newline at end of file
+#define LWIP_UDP 0
diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv4only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv4only.h
--- contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv4only.h	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv4only.h	2022-03-19 15:08:48.590646888 +0100
@@ -1,4 +1,4 @@
 #include "test_configs/opt_ipv4only.h"
 
 #undef LWIP_UDP
-#define LWIP_UDP 0
\ No newline at end of file
+#define LWIP_UDP 0
diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv6only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv6only.h
--- contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv6only.h	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv6only.h	2022-03-19 15:08:52.490588248 +0100
@@ -1,4 +1,4 @@
 #include "test_configs/opt_ipv6only.h"
 
 #undef LWIP_UDP
-#define LWIP_UDP 0
\ No newline at end of file
+#define LWIP_UDP 0
diff -ruN contrib-2.1.0/ports/CMakeCommon.cmake contrib-2.1.0-P/ports/CMakeCommon.cmake
--- contrib-2.1.0/ports/CMakeCommon.cmake	2018-09-04 22:54:08.000000000 +0200
+++ contrib-2.1.0-P/ports/CMakeCommon.cmake	2022-03-19 15:03:40.651279436 +0100
@@ -73,7 +73,6 @@
                 -fsanitize=undefined
                 -fno-sanitize=alignment
                 -fstack-protector
-                -fstack-check
             )
             set(LWIP_SANITIZER_LIBS asan ubsan)
         endif()
diff -ruN contrib-2.1.0/ports/unix/check/CMakeLists.txt contrib-2.1.0-P/ports/unix/check/CMakeLists.txt
--- contrib-2.1.0/ports/unix/check/CMakeLists.txt	2018-09-04 22:54:08.000000000 +0200
+++ contrib-2.1.0-P/ports/unix/check/CMakeLists.txt	2022-03-19 15:03:40.651279436 +0100
@@ -7,14 +7,12 @@
 endif()
 
 set(LWIP_CONTRIB_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../..)
-set(LWIP_DIR         ${CMAKE_CURRENT_SOURCE_DIR}/../../../../lwip)
 
 set(LWIP_USE_SANITIZERS true)
 include(${LWIP_CONTRIB_DIR}/ports/CMakeCommon.cmake)
 
 if(CMAKE_C_COMPILER_ID STREQUAL Clang)
     # check.h causes 'error: token pasting of ',' and __VA_ARGS__ is a GNU extension' with clang 9.0.0
-    list(LWIP_COMPILER_FLAGS APPEND -Wno-gnu-zero-variadic-macro-arguments)
 endif()
 
 set (LWIP_DEFINITIONS -DLWIP_DEBUG -DLWIP_NOASSERT_ON_ERROR)
diff -ruN contrib-2.1.0/ports/unix/example_app/iteropts.sh contrib-2.1.0-P/ports/unix/example_app/iteropts.sh
--- contrib-2.1.0/ports/unix/example_app/iteropts.sh	2018-09-12 22:16:02.000000000 +0200
+++ contrib-2.1.0-P/ports/unix/example_app/iteropts.sh	2022-03-19 15:03:40.651279436 +0100
@@ -1,24 +1,34 @@
-#!/bin/bash
-
-LOGFILE=iteropts.log
-EXAPPDIR=../../../examples/example_app
-
-pushd `dirname "$0"`
-pwd
-echo Starting Iteropts run >> $LOGFILE
-for f in $EXAPPDIR/test_configs/*.h
-do
-    echo Cleaning...
-    make clean
-    BUILDLOG=$(basename "$f" ".h").log
-    echo testing $f
-    echo testing $f >> $LOGFILE
-    rm $EXAPPDIR/lwipopts_test.h
-    # cat the file to update its timestamp
-    cat $f > $EXAPPDIR/lwipopts_test.h
-    make TESTFLAGS=-DLWIP_OPTTEST_FILE -j 8 &> $BUILDLOG 2>&1 || echo file $f failed >> $LOGFILE
-    echo test $f done >> $LOGFILE
-done
-echo done, cleaning
-make clean
-popd
+#!/bin/bash
+
+LOGFILE=iteropts.log
+EXAPPDIR=../../../examples/example_app
+RETVAL=0
+
+pushd `dirname "$0"`
+pwd
+echo Starting Iteropts run >> $LOGFILE
+for f in $EXAPPDIR/test_configs/*.h
+do
+    echo Cleaning...
+    make clean > /dev/null
+    BUILDLOG=$(basename "$f" ".h").log
+    echo testing $f
+    echo testing $f >> $LOGFILE
+    rm -f $EXAPPDIR/lwipopts_test.h
+    # cat the file to update its timestamp
+    cat $f > $EXAPPDIR/lwipopts_test.h
+    make TESTFLAGS="-DLWIP_OPTTEST_FILE -Wno-documentation" -j 4 1> $BUILDLOG 2>&1
+    ERR=$?
+    if [ $ERR != 0 ]; then
+        cat $BUILDLOG
+        echo file $f failed with $ERR >> $LOGFILE
+        echo ++++++++ $f FAILED +++++++
+        RETVAL=1
+    fi
+    echo test $f done >> $LOGFILE
+done
+echo done, cleaning
+make clean > /dev/null
+popd
+echo Exit value: $RETVAL
+exit $RETVAL
diff -ruN contrib-2.1.0/ports/unix/port/include/arch/sys_arch.h contrib-2.1.0-P/ports/unix/port/include/arch/sys_arch.h
--- contrib-2.1.0/ports/unix/port/include/arch/sys_arch.h	2018-07-12 21:24:16.000000000 +0200
+++ contrib-2.1.0-P/ports/unix/port/include/arch/sys_arch.h	2022-03-19 15:05:59.193194629 +0100
@@ -59,5 +59,8 @@
 struct sys_thread;
 typedef struct sys_thread * sys_thread_t;
 
+#define LWIP_EXAMPLE_APP_ABORT() lwip_unix_keypressed()
+int lwip_unix_keypressed(void);
+
 #endif /* LWIP_ARCH_SYS_ARCH_H */
 
diff -ruN contrib-2.1.0/ports/unix/port/sys_arch.c contrib-2.1.0-P/ports/unix/port/sys_arch.c
--- contrib-2.1.0/ports/unix/port/sys_arch.c	2018-09-04 22:02:58.000000000 +0200
+++ contrib-2.1.0-P/ports/unix/port/sys_arch.c	2022-03-19 15:07:13.416078142 +0100
@@ -717,3 +717,14 @@
     }
 }
 #endif /* SYS_LIGHTWEIGHT_PROT */
+
+/* get keyboard state to terminate the debug app by using select */
+int
+lwip_unix_keypressed(void)
+{
+  struct timeval tv = { 0L, 0L };
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(0, &fds);
+  return select(1, &fds, NULL, NULL, &tv);
+}