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sh-3.1$ bitbake base-image
NOTE: Psyco JIT Compiler (http://psyco.sf.net) not available. Install it to increase performance.
NOTE: Handling BitBake files: \ (0526/5256) [10 %]NOTE: <type 'exceptions.TypeError'>:unsupported operand type(s) for +: 'NoneType' and 'str' while evaluating:
    ${@base_contains('COMBINED_FEATURES', 'pci', 'madwifi-ng-modules', '',d)}     ${@base_contains('COMBINED_FEATURES', 'usbhost', 'kernel-module-zd1211rw', '',d)}     kernel-module-ieee80211-crypt     kernel-module-ieee80211-crypt-ccmp     kernel-module-ieee80211-crypt-tkip     kernel-module-ieee80211-crypt-wep     kernel-module-ecb     kernel-module-arc4     kernel-module-crypto_algapi     kernel-module-cryptomgr     kernel-module-michael-mic     ${@base_version_less_or_equal("KERNEL_VERSION", "2.6.23", "kernel-module-aes", "kernel-module-aes-generic", d)} 
ERROR: unsupported operand type(s) for +: 'NoneType' and 'str' while parsing /home/nice/SlackPAD/oe/org.openembedded.dev/packages/tasks/task-base.bb
NOTE: Handling BitBake files: | (5256/5256) [100 %]
NOTE: Parsing finished. 5026 cached, 1 parsed, 229 skipped, 0 masked.
ERROR: Parsing errors found, exiting...