diff -r 0acc5626a578 Mac/BuildScript/build-installer.py
--- a/Mac/BuildScript/build-installer.py	Tue Oct 23 22:50:11 2012 +0100
+++ b/Mac/BuildScript/build-installer.py	Thu Oct 25 00:34:51 2012 +0300
@@ -646,6 +646,12 @@
                 shutil.rmtree(retval)
             fp = os.popen("tar jxf %s 2>&1"%(shellQuote(archiveName),), 'r')
 
+        elif archiveName.endswith('.tar.xz'):
+            retval = os.path.basename(archiveName[:-7])
+            if os.path.exists(retval):
+                shutil.rmtree(retval)
+            fp = os.popen("tar Jxf %s 2>&1"%(shellQuote(archiveName),), 'r')
+
         elif archiveName.endswith('.tar'):
             retval = os.path.basename(archiveName[:-4])
             if os.path.exists(retval):
@@ -759,6 +765,9 @@
         if fn.endswith('.bz2'):
             runCommand('bunzip2 -fk %s' % shellQuote(fn))
             fn = fn[:-4]
+        elif fn.endswith('.xz'):
+            runCommand('unxz -fk %s' % shellQuote(fn))
+            fn = fn[:-3]
         runCommand('sh %s' % shellQuote(fn))
         os.unlink(fn)