snapcraft has many exit points

[Leo Arias]

I think it should be better to raise exceptions on many of these cases that exit with 1.
Then, the main method can catch the exceptions, and exit with 1.

For the cases that exit with 0, we should just return to the main caller.

elopio@calchas:~/workspace/canonical/snapcraft/trunk$ grep -r sys.exit
snapcraft/cmds.py: sys.exit(1)
snapcraft/cmds.py: sys.exit(0)
snapcraft/cmds.py: sys.exit(1)
snapcraft/cmds.py: sys.exit(1)
snapcraft/cmds.py: sys.exit(1)
snapcraft/plugins/ant_project.py: sys.exit(1)
snapcraft/plugins/ubuntu.py: sys.exit(1)
snapcraft/plugins/ubuntu.py: sys.exit(1)
snapcraft/main.py: sys.exit(1)
snapcraft/main.py: sys.exit(0)
snapcraft/yaml.py: sys.exit(1)
snapcraft/yaml.py: sys.exit(1)
snapcraft/yaml.py: sys.exit(1)
snapcraft/plugin.py: sys.exit(1)
snapcraft/common.py: sys.exit(1)

[Zygmunt Krynicki (zyga)]

Leo, I would strongly recommend you to have a look at guacamole to organize all of snapcraft CLI handling. Let's discuss this next week. I would love to work with you to get this merged.

[Leo Arias (elopio)]

@zyga, sergiusens will be the main developer. You should tell him to consider that option. He'll probably look at this bug soon anyway.

[Sergio Schvezov (sergiusens)]

I removed a couple of the exits points, it is a bit cleaner now.

We can reopen this bug again I guess if necessary