Add _GNU_SOURCE to find pthread_mutexattr_init and display gcc version during build

build.xml

@@ -54,6 +54,11 @@
       <property name="ldflags.so" value="-fvisibility=hidden -shared" />
       <mkdir dir="${output.folder}"/>
 
+      <!-- display gcc version -->
+      <exec executable="gcc" failonerror="true">
+        <arg line="-v"/>	
+      </exec>
+
       <!-- non-SSL, synchronous library -->
       <property name="output.filename" value="${output.folder}/lib${libname}.so" /> 
       <exec executable="gcc" failonerror="true">

src/MQTTAsync.c

@@ -25,7 +25,7 @@
  *
  */
 
-#define _GNU_SOURCE
+#define _GNU_SOURCE /* for pthread_mutexattr_settype */
 #include <stdlib.h>
 #if !defined(WIN32)
 	#include <sys/time.h>

src/MQTTClient.c

@@ -18,6 +18,7 @@
  *    Ian Craggs - multiple server connection support
  *    Ian Craggs - fix for bug 413429 - connectionLost not called
  *    Ian Craggs - fix for bug 421103 - trying to write to same socket, in publish/retries
+ *    Ian Craggs - fix for bug 419233 - mutexes not reporting errors
  *******************************************************************************/
 
 /**
@@ -26,6 +27,7 @@
  *
  */
 
+#define _GNU_SOURCE /* for pthread_mutexattr_settype */
 #include <stdlib.h>
 #if !defined(WIN32)
 	#include <sys/time.h>