=> Bootstrap dependency digest>=20010302: found digest-20121220
=> Checksum SHA1 OK for PyYAML-3.10.tar.gz
=> Checksum RMD160 OK for PyYAML-3.10.tar.gz
===> Installing dependencies for py33-yaml-3.10
==========================================================================
The following variables will affect the build process of this package,
py33-yaml-3.10.  Their current value is shown below:

        * PYTHON_VERSION_DEFAULT = 27

Based on these variables, the following variables have been set:

        * PYPACKAGE = python33

You may want to abort the process now with CTRL-C and change their value
before continuing.  Be sure to run `/usr/bin/make clean' after
the changes.
==========================================================================
=> Tool dependency checkperms>=1.1: found checkperms-1.11
=> Full dependency python33>=3.3: found python33-3.3.2
===> Overriding tools for py27-yaml-3.10
===> Extracting for py27-yaml-3.10
===> Patching for py27-yaml-3.10
===> Creating toolchain wrappers for py27-yaml-3.10
ERROR: python27>=2.7 python27>=2.7 is not installed; can't buildlink files.
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/wip/py-yaml
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/wip/py-yaml