Is it normal for Xcode not to detect if a pre-action failed?

I am using Xcode 4 and I added an preaction to the run scheme, a bash script, but it seems that Xcode is ignoring the exit status of the script and always run, even if the exit code is not zero.

Is this normal? What alternatives do I have for adding a custom step, one that can fail?

Update: I also tried exit 1 for post-action for build but with the same results, always executing without any feedback.

How can I make a custom step that can mark the build as failed?