python-minimal gets unpacked in line 343 that provides the updated debian_defaults file.
The python2.6-minimal postinst is run in line 280:
...
Selecting previously deselected package python2.6-minimal.^M
(Reading database ... 12964 files and directories currently installed.)^M
Unpacking python2.6-minimal (from .../python2.6-minimal_2.6.1-1ubuntu7_amd64.deb) ...^M
Setting up python2.6-minimal (2.6.1-1ubuntu7) ...^M
^M
So it seems like the rtinstall postinst thinks that 2.6 is not a supported runtime and does not bytecompile.
python-minimal gets unpacked in line 343 that provides the updated debian_defaults file.
The python2.6-minimal postinst is run in line 280: 6-minimal. ^M 6-minimal_ 2.6.1-1ubuntu7_ amd64.deb) ...^M
...
Selecting previously deselected package python2.
(Reading database ... 12964 files and directories currently installed.)^M
Unpacking python2.6-minimal (from .../python2.
Setting up python2.6-minimal (2.6.1-1ubuntu7) ...^M
^M
So it seems like the rtinstall postinst thinks that 2.6 is not a supported runtime and does not bytecompile.