lava_test_shell's testdef_repos assumes flat repo layout

I'm trying new testdef_repos functionality with:

    {
        "command": "lava_test_shell",
        "parameters": {
            "testdef_repos": [
                {
                    "bzr-repo": "lp:~linaro-infrastructure/cbuild/lava-build-slave",
                    "testdef": "slaves/lava-build/cbuild-gcc-mockbuild.yaml"
                }
            ],
            "timeout": 36000
        }
    },

I get (with added debug output):

Traceback (most recent call last):
  File "/srv/lava/instances/cbuild/code/r85/bin/lava", line 65, in <module>
    lava.tool.main.LavaDispatcher.run()
  File "/srv/lava/.cache/eggs/lava_tool-0.6-py2.7.egg/lava/tool/dispatcher.py", line 147, in run
    raise SystemExit(cls().dispatch(args))
  File "/srv/lava/.cache/eggs/lava_tool-0.6-py2.7.egg/lava/tool/dispatcher.py", line 137, in dispatch
    return command.invoke()
  File "/srv/lava/.cache/eggs/lava_dispatcher-0.23-py2.7.egg/lava/dispatcher/commands.py", line 100, in invoke
shutil.copy2( tmp0wcFLd/tmpteTXJU/bzrtestrepo/report.sh , /tmp/tmpeMZDKU/lava/tests/0_cbuild-gcc )

shutil.copy2( tmp0wcFLd/tmpteTXJU/bzrtestrepo/start.sh , /tmp/tmpeMZDKU/lava/tests/0_cbuild-gcc )
shutil.copy2( tmp0wcFLd/tmpteTXJU/bzrtestrepo/files , /tmp/tmpeMZDKU/lava/tests/0_cbuild-gcc )
Lava failed at action lava_test_shell with error:[Errno 21] Is a directory: 'tmp0wcFLd/tmpteTXJU/bzrtestrepo/files'

So, there're 2 issues: 1) testdef_repos doesn't expect the repo to contain any subdirectories, and bails out if it does, which is definitely a bug. And 2) it's not necessarily does what user expect - in this particular case, it's a repo for standalone project, and lava testdef are just part of it, in one of subdirs. Just copying top-level files doesn't help much, and testdef_repos can't really know which files of a repo a user may need. Assuming it's too cumbersome to list all needed files explicitly, it would make sense to just copy over entire repo checkout recursively, which would solve both issues.