diff -r 8ca90cef0183 -r 45525a59768b SConstruct
--- a/SConstruct	Tue Jan 08 08:54:16 2013 -0500
+++ b/SConstruct	Wed Jan 09 17:22:28 2013 +0000
@@ -637,21 +637,31 @@
         termcap.Normal
     main['PROTOC'] = False
 else:
-    # Determine the appropriate include path and library path using
-    # pkg-config, that means we also need to check for pkg-config
-    if not readCommand(['pkg-config', '--version'], exception=''):
-        print 'Error: pkg-config not found. Please install and retry.'
-        Exit(1)
-
-    main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
-
     # Based on the availability of the compress stream wrappers,
     # require 2.1.0
     min_protoc_version = '2.1.0'
     if compareVersions(protoc_version[1], min_protoc_version) < 0:
-        print 'Error: protoc version', min_protoc_version, 'or newer required.'
-        print '       Installed version:', protoc_version[1]
-        Exit(1)
+        print termcap.Yellow + termcap.Bold + \
+            'Warning: protoc version', min_protoc_version, \
+            'or newer required.\n' + \
+            '         Installed version:', protoc_version[1]
+        main['PROTOC'] = False
+    else:
+        # Attempt to determine the appropriate include path and
+        # library path using pkg-config, that means we also need to
+        # check for pkg-config. Note that it is possible to use
+        # protobuf without the involvement of pkg-config. Later on we
+        # check go a library config check and at that point the test
+        # will fail if libprotobuf cannot be found.
+        if readCommand(['pkg-config', '--version'], exception=''):
+            try:
+                # Attempt to establish what linking flags to add for protobuf
+                # using pkg-config
+                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
+            except:
+                print termcap.Yellow + termcap.Bold + \
+                    'Warning: pkg-config could not get protobuf flags.' + \
+                    termcap.Normal
 
 # Check for SWIG
 if not main.has_key('SWIG'):