Index: tools/autotool.py
===================================================================
--- tools/autotool.py	(revision 57292d30b3826ea0794eb52897209d68bd98d76b)
+++ tools/autotool.py	(revision ef3da5ad625620e40458132c67c6c8d18ecf31fe)
@@ -355,4 +355,18 @@
 	check_app([common['OBJDUMP'], "--version"], "GNU Objdump utility", details)
 	check_app([common['STRIP'], "--version"], "GNU strip", details)
+
+def check_python():
+	"Check for Python dependencies"
+	
+	try:
+		sys.stderr.write("Checking for PyYAML ... ")
+		import yaml
+	except ImportError:
+		print_error(["PyYAML is missing.",
+		             "",
+		             "Please make sure that it is installed in your",
+		             "system (usually part of PyYAML package)."])
+	
+	sys.stderr.write("ok\n")
 
 def decode_value(value):
@@ -810,4 +824,6 @@
 			common['CLANG_TARGET'] = clang_target
 		
+		check_python()
+		
 		# Platform-specific utilities
 		if ((config['BARCH'] == "amd64") or (config['BARCH'] == "ia32") or (config['BARCH'] == "ppc32") or (config['BARCH'] == "sparc64")):