Trying to debug a trybot failure on cast_shell_linux, I noticed that the "analyze" step can fail with an error, but still appear green in the bot output.

As a recent example:

https://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linux/builds/260851

In this case, the analyze step reports invalid targets, and terminates with an error. For some reason (perhaps the return value of the executable) the step is still shown as green (passing).