Index: doc/bitbake.1
===================================================================
--- doc/bitbake.1	(Revision 1067)
+++ doc/bitbake.1	(Arbeitskopie)
@@ -97,13 +97,18 @@
 .B \-IIGNORED\_DOT\_DEPS, \-\-ignore-deps=IGNORED_DOT_DEPS
 Stop processing at the given list of dependencies when generating dependency
 graphs. This can help to make the graph more appealing
-.\"
-.\" Next option is only in BitBake 1.7.x (trunk)
-.\"
-.\".TP
-.\".B \-lDEBUG_DOMAINS, \-\-log-domains=DEBUG_DOMAINS
-.\"Show debug logging for the specified logging domains
+.TP
+.B \-lDEBUG_DOMAINS, \-\-log-domains=DEBUG_DOMAINS
+Show debug logging for the specified logging domains
+.TP
+.B \-P, \-\-profile
+profile the command and print a report
+.TP
+.B \-S, \-\-sane-environment
+Do not clean the environment variables. Use this on your own risk.
+.TP
 
+
 .SH AUTHORS
 BitBake was written by 
 Phil Blundell,
Index: doc/manual/usermanual.xml
===================================================================
--- doc/manual/usermanual.xml	(Revision 1067)
+++ doc/manual/usermanual.xml	(Arbeitskopie)
@@ -415,6 +415,10 @@
                         the graph more appealing
   -l DEBUG_DOMAINS, --log-domains=DEBUG_DOMAINS
                         Show debug logging for the specified logging domains
+  -P, --profile         profile the command and print a report
+  -S, --sane-environment
+                        Do not clean the environment variables. Use this on
+                        your own risk.
 
 </screen>
                 </para>
Index: bin/bitbake
===================================================================
--- bin/bitbake	(Revision 1067)
+++ bin/bitbake	(Arbeitskopie)
@@ -42,6 +42,56 @@
 
 
 #============================================================================#
+# clean_environment 
+#============================================================================#
+def clean_environment():
+    """
+    Create a pristine environment for bitbake. This will remove variables that
+    are not known and may influence the build in a negative way.
+    """
+    good_keys = [
+        "BBPATH",
+        "COLORTERM",
+        "DBUS_SESSION_BUS_ADDRESS",
+        "DESKTOP_SESSION",
+        "DESKTOP_STARTUP_ID",
+        "DISPLAY",
+        "GNOME_KEYRING_PID",
+        "GNOME_KEYRING_SOCKET",
+        "GPG_AGENT_INFO",
+        "GTK_RC_FILES",
+        "HOME",
+        "LANG",
+        "LOGNAME",
+        "PATH",
+        "PWD",
+        "SESSION_MANAGER",
+        "SHELL",
+        "SSH_AUTH_SOCK",
+        "TERM",
+        "USER",
+        "USERNAME",
+        "_",
+        "XAUTHORITY",
+        "XDG_DATA_DIRS",
+        "XDG_SESSION_COOKIE",
+    ]
+
+
+    removed_vars = []
+    for key in os.environ.keys():
+        if key in good_keys:
+            continue
+        
+        removed_vars.append(key)
+        os.unsetenv(key)
+        del os.environ[key]
+
+    if len(removed_vars):
+        bb.note("Removed the following variables from the environment:", ",".join(removed_vars))
+
+
+#============================================================================#
 # main
 #============================================================================#
 
@@ -105,6 +155,9 @@
     parser.add_option( "-P", "--profile", help = "profile the command and print a report",
                action = "store_true", dest = "profile", default = False )
 
+    parser.add_option( "-S", "--sane-environment", help = """Do not clean the environment variables. Use this on your own risk.""",
+                action = "store_false", dest = "clean_environment", default = True)
+
     options, args = parser.parse_args(sys.argv)
 
     configuration = BBConfiguration(options)
@@ -112,6 +165,8 @@
     configuration.pkgs_to_build.extend(args[1:])
 
     cooker = bb.cooker.BBCooker(configuration)
+    if options.clean_environment:
+        clean_environment()
 
     if configuration.profile:
         try: