Description of problem:
The image deshuai/ruby-20-centos is just a copy of openshift/ruby-20-centos with the tar package removed.
The image deshuai/wildfly-8-centos is just a copy of openshift/wildfly-8-centos with the tar package removed.
When I use the "deshuai/ruby-20-centos" or "deshuai/wildfly-8-centos" to do sti build , it failed.But when I add the tar back to the base image, it can build successfully. when don't have the tar, but remove the default user in the image, it can also build successfully.

Version-Release number of selected component (if applicable):
devenv-fedora_593

How reproducible:
Always

Steps to Reproduce:
1. [fedora@ip-10-230-176-209 tmp]$ sti build git://github.com/pmorie/simple-ruby deshuai/ruby-20-centos test-ruby-app -s https://raw.githubusercontent.com/openshift/ruby-20-centos/master/.sti/bin
I0126 05:30:37.077156 23326 build.go:71] Building test-ruby-app
Cloning into '/tmp/sti275781904/upload/src'...
remote: Counting objects: 9, done.
remote: Total 9 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (9/9), done.
Resolving deltas: 100% (1/1), done.
Checking connectivity... done.
W0126 05:30:40.205613 23326 build.go:114] Image deshuai/ruby-20-centos does not have tar! Performing additional build to add the scripts and sources.
E0126 05:31:02.049975 23326 main.go:184] An error occurred: assemble for test-ruby-app failed:
E0126 05:31:02.050021 23326 main.go:185] Suggested solution: check the assemble script output for errors
E0126 05:31:02.050031 23326 main.go:191] If the problem persists consult the docs at https://github.com/openshift/source-to-image/tree/master/docs.Eventually reach us on freenode #openshift or file an issue at https://github.com/openshift/source-to-image/issues providing us with a log from your build using --loglevel=3

2. [fedora@ip-10-230-176-209 tmp]$ sti build git://github.com/bparees/openshift-jee-sample deshuai/wildfly-8-centos test-jee-app
I0126 05:39:14.152624 24348 build.go:71] Building test-jee-app
Cloning into '/tmp/sti529061109/upload/src'...
remote: Counting objects: 29, done.
remote: Compressing objects: 100% (19/19), done.
remote: Total 29 (delta 1), reused 29 (delta 1)
Receiving objects: 100% (29/29), 22.84 KiB | 0 bytes/s, done.
Resolving deltas: 100% (1/1), done.
Checking connectivity... done.
W0126 05:39:17.412344 24348 build.go:114] Image deshuai/wildfly-8-centos does not have tar! Performing additional build to add the scripts and sources.
E0126 05:39:40.042002 24348 main.go:184] An error occurred: assemble for test-jee-app failed:
E0126 05:39:40.042049 24348 main.go:185] Suggested solution: check the assemble script output for errors
E0126 05:39:40.042059 24348 main.go:191] If the problem persists consult the docs at https://github.com/openshift/source-to-image/tree/master/docs.Eventually reach us on freenode #openshift or file an issue at https://github.com/openshift/source-to-image/issues providing us with a log from your build using --loglevel=3

Actual results:
1.sti build failed.
2.sti build failed.

Expected results:
1.sti build successfully.
2.sti build successfully.

Additional info:
http://ur1.ca/jjjhe
http://ur1.ca/jjjhq
When I remove the user in the image , it can build successfully.