Murad,
the first difference is that you are using different CFG scripts. For Debug, you are using EDACS_INBND_DIAGNOSTX_DSP.cfg, while for Release you are using custom/hpdspua/evmc6678l/package/build.cfg. I am pretty sure that the latter one should not be used because it's an internal file for a package custom.hpdspua.evm6678l. You have to fix that first, I am guessing both configurations should use the same CFG script.
There are other references to the package in that custom directory? You are somehow including subdir_rules.mk from that package. Why does that package even have subdir_rules.mk? Only CCS projects have that file, and CCS is not typically used to build RTSC packages.
Also, the generated C file custom/hpdspua/evmc6678l/package/package_custom.hpdspua.evmc6678l.c is being rebuilt in the course of building the project, and that doesn't seem correct. That file is built when the package is built and after that a package should deliver a library that contains the generated object file. I am not sure how you ended up with that invalid Release configuration, but all the references to other projects and CFG scripts should all be the same.