Crash after manual build step execution

[jkloetzke]

Executed build.sh manually and then called Bob again for the same package:

An internal Exception has occured. This should not have happenend.
Please open an issue at https://github.com/BobBuildTool/bob with the following backtrace:
Bob version 0.12.0-56-g2a4b0a1
Traceback (most recent call last):
  File "/home/kloetzke/src/bob/pym/bob/scripts.py", line 115, in catchErrors
    ret = fun(*args, **kwargs)
  File "/home/kloetzke/src/bob/pym/bob/scripts.py", line 195, in cmd
    availableCommands[args.command][1](args.args, bobRoot)
  File "/home/kloetzke/src/bob/pym/bob/scripts.py", line 38, in __develop
    doDevelop(*args, **kwargs)
  File "/home/kloetzke/src/bob/pym/bob/cmds/build.py", line 1089, in doDevelop
    commonBuildDevelop(parser, argv, bobRoot, True)
  File "/home/kloetzke/src/bob/pym/bob/cmds/build.py", line 1048, in commonBuildDevelop
    builder.cook([p], p.getPackage(), True if args.build_mode == 'checkout-only' else False)
  File "/home/kloetzke/src/bob/pym/bob/cmds/build.py", line 577, in cook
    self._cookPackageStep(step, checkoutOnly, depth)
  File "/home/kloetzke/src/bob/pym/bob/cmds/build.py", line 868, in _cookPackageStep
    audit = self._generateAudit(packageStep, depth, packageHash)
  File "/home/kloetzke/src/bob/pym/bob/cmds/build.py", line 377, in _generateAudit
    audit.addArg(os.path.join(dep.getWorkspacePath(), "..", "audit.json.gz"))
  File "/home/kloetzke/src/bob/pym/bob/audit.py", line 387, in addArg
    audit = Audit.fromFile(arg)
  File "/home/kloetzke/src/bob/pym/bob/audit.py", line 275, in fromFile
    with gzip.open(file, 'rb') as gzf:
  File "/usr/lib/python3.4/gzip.py", line 52, in open
    binary_file = GzipFile(filename, gz_mode, compresslevel)
  File "/usr/lib/python3.4/gzip.py", line 181, in __init__
    fileobj = self.myfileobj = builtins.open(filename, mode or 'rb')
FileNotFoundError: [Errno 2] No such file or directory: 'dev/build/[snip]/1/workspace/../audit.json.gz'