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On Wheezy, follow the additional instructions here: Debian Wheezy packages.
Bash vs Bourne
Be sure that your build system is using bash as the default system shell. Both Debian and Ubuntu use dash instead and the 'bashisms' in a lot of the build metadata will cause failures unless /bin/sh is a symlink to /bin/bash. The Ubuntu section of of the OE and Your Distro describes a work-around for this issue.
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