Description of problem:
If rpc is in a tree on Atomic, then it won't start, because it seems that it is directly (not indirectly through libs) checking that the rpc user exists in /etc/passwd.
But as users are in /usr/lib/passwd on Atomic, rpcbind refuses to start:

Logs:
Aug 31 08:46:38 atomic01.example.org systemd[1]: Starting RPC bind service...
Aug 31 08:46:38 atomic01.example.org systemd[1]: Started RPC bind service.
Aug 31 08:46:38 atomic01.example.org rpcbind[776]: cannot get uid of 'rpc': Success
Aug 31 08:46:38 atomic01.example.org systemd[1]: rpcbind.service: main process exited, code=exited, status=1/FAILURE
Aug 31 08:46:38 atomic01.example.org systemd[1]: Unit rpcbind.service entered failed state.


Version-Release number of selected component (if applicable):
# rpm -q rpcbind
rpcbind-0.2.0-26.el7.x86_64


How reproducible:
Always

Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:
To make it work:

# cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
centos:x:1000:1000:Cloud User:/home/centos:/bin/bash

# grep rpc /usr/lib/passwd >> /etc/passwd

# service rpcbind restart
Redirecting to /bin/systemctl restart  rpcbind.service
# systemctl status rpcbind
rpcbind.service - RPC bind service
   Loaded: loaded (/usr/lib/systemd/system/rpcbind.service; static)
   Active: active (running) since Fr 2015-09-04 07:56:14 UTC; 4s ago
  Process: 13656 ExecStart=/sbin/rpcbind -w ${RPCBIND_ARGS} (code=exited, status=0/SUCCESS)
 Main PID: 13657 (rpcbind)
   CGroup: /system.slice/rpcbind.service
           └─13657 /sbin/rpcbind -w