Do not allow overwriting files

[hexylena]

@natefoo could you add a sudoers entry for the user jenkins SSHs as into depot, for the following command:

sudo chattr -i /srv/.... (where ... is the path to cargo port's software directory).

[martenson]

one thing to note is that given that jenkins also has executors on other machine(s) we need to do all these changes on all of them :/

[hexylena]

This would only be on orval. No packages are downloaded on the jenkins machines themselves.

[natefoo]

On illumos this will be /usr/bin/chmod S+ci /srv/..., except I will need to figure out if there's a zfs privilege or acl that allows unprivileged users to do this.

[hexylena]

Thanks for looking into it!