On UNIX, using the allocation override with SUBDIR($ENVVAR) in the config file doesn't seem to be able to recognise the AllocOverride.cfg file allocations.

For example, having an allocation override of:

OFFSET(324) VALUE(VSAM) SUBDIR($VSAMPATH)  create the datasets in the allocated default dataset location.

On UNIX, we cannot expand a path that contains only an environment variable. It must contain the environment and a slash and additional
directory in which the files for those datasets will be created.

Changing this to:
OFFSET(324) VALUE(VSAM) SUBDIR($VSAMPATH/PRODV) will avoid the problem.