CPU12.1.0.2.3 opatchauto failed with error code 255.

Question

I am installing critical patch update 12.1.0.2.3 (15-APR-2015) for Grid Infrastructure standalone on Linux.  It fails with the subject error code and the following additional messages:,
The user is root. OPatch cannot continue if the user is root.
opatchauto failed with error code 255.
The instructions specifically tell me to login as root before installing the patch, so what's up?
The instructions say to first upgrade OPatch to the latest, which I have done and verified.
Second, an OCM Response File is mandatory, so I followed the steps to create this file and saved it as /home/grid/ocm.rsp with default permissions 644.
Third, the instructions say to download the patch and unzip it to an empty location that cannot be /tmp.  I created a new directory /home/grid/foo and unzipped the software to that location.  So, the unzip location is /home/grid/foo/ and in that directory are only two things: a file named PatchSearch.xml and a directory named 20485724.
Fourth, the readme says the patch must be installed by a user with root privileges, so I have logged in as root.  (Oracle Note 1591616.1 says you must login as root, not just be root like). 
As root I have set environment variable for ORACLE_HOME pointing to the GI Home, and I set PATH=$PATH:$ORACLE_HOME/bin:$ORACLE_HOME/OPatch. 
Finally, I invoke opatchauto with the required parameters and it throws an error saying I cannot be root.  I fussed with the parameters and the result is always I cannot be root.
From the documentation,
Case 3: Patching GI Home Alone
You should use the following instructions if you prefer to patch Oracle GI (Grid Infrastructure) home alone with this patch.
Case 3.1: Non-Shared GI Home
If the GI home is not shared then use the following instructions to patch the home.
Case 3.1.1: ACFS File System Is Not Configured
Follow these instructions in this section if the GI home is not shared and none of the Oracle database homes use ACFS file system for its software files.
Execute the following on each node of the cluster.
As root user execute:
# opatchauto apply <UNZIPPED_PATCH_LOCATION>/%BUGNO% -oh <GI_HOME> -ocmrf <ocm response file>
My command is,
opatchauto apply /home/grid/foo/20485724 -oh /u01/app/12.1.0.2/grid -ocmrf /home/grid/ocm.rsp
So, not a syntax problem.  It simply won't let me run it as root despite that being a hard requirement.

Answer 1

Hello,
I tried with above command and faced the a different error . I tried applying patch 4487801.
ApplySession applying interim patch '4487801' to OH <Oracle_Home>
ApplySession failed during prerequisite checks: Prerequisite check "CheckApplica
bleProduct" failed.
The details are:
OPatch found incompatible or invalid applicable product type with respect to the
Oracle Home.
System intact, OPatch will not attempt to restore the system
OPatch failed with error code = 74
I doubt if some other patches to be applied before this one.if yes, then from where we can get the list of pre requite patches.
Please guide.