ID 252916 - Setting color management from 'Nuke' to 'OCIO' initially errors in some default LUT settings, when config.ocio set by OCIO environment variable AND .py argument in Nuke launch

Problem summary
Changing root color management from 'Nuke' to 'OCIO' initially errors in some default LUT settings, when config.ocio set by OCIO environment variable AND .py argument in Nuke launch

Customer reported version
nuke.10.0v4

Customer reported platform
centos6

Steps to reproduce


1) set OCIO environment variable to point to a valid config.ocio and luts

sample used for this test is at /<share>/<this bug#>/003.tar.gz

2) launch Nuke10.5v1 with .py script argument

this is enough to have in the file:

print "hello world!"

3) hit s in node graph and change color management knob

Workaround
If you toggle the color management knob back to 'Nuke' and then to 'OCIO' again, the default LUT settings appear correct

Reproduced by support
repro'd on Nuke9.0v8, 10.0v5, 10.5v1 
on OS 10.10.5

Expected behaviour
default LUT settings correct the first time you set them

Actual behaviour
default LUT settings incorrect the first time you set them