Daniel Westermann's Blog

if you do a solaris 10u11 core/minimal installation and after that add all packages listed in the documentation the oracle database 12.1.0.2 software installation will fail with:

WARNING: Verification of target environment returned with errors.
WARNING: [WARNING] [INS-13001] Environment does not meet minimum requirements.
CAUSE: Minimum requirements were not met for this environment
ACTION: Either check the logs for more information or check the supported configurations for this product..
Refer associated stacktrace #oracle.install.commons.util.exception.DefaultErrorAdvisor:339
INFO: Advice is CONTINUE
WARNING: Advised to ignore target environment verification errors.
INFO: Verifying setup for installer validations
INFO: Overall status of CVU API call:OPERATION_FAILED
SEVERE: [FATAL] [INS-30131] Initial setup required for the execution of installer validations failed.
CAUSE: Failed to access the temporary location.
ACTION: Ensure that the current user has required permissions to access the temporary location.

this is a bit misleading. the real cause of this (at least in my case) are missing packages:

SUNWpool
SUNWpoolr

once these are installed the installation will succeed.