if Mac.OS requires the currently running OS X version to be included in the options

[vitorgalvao]

Here’s an oddity I’ve noticed when working on #7813. Not sure if a bug or a feature.

Error: Cask 'keyremap4macbook' definition is invalid: 'url' stanza failed with: wrong number of arguments (0 for 1..2)

When using if MacOS.version, one of the options must refer to the latest OS X version (:yosemite) and have a valid url or we get the above error. This means it’s a requirement to have the equivalent to elsif > any_version_except_:yosemite, elsif <= :yosemite, elsif == :yosemite, or else, and those must have a valid url. If any of the first options are included, else can be safely excluded.

This can be seen as feature in that it tries to make sure the if logic addresses the latest version of the OS, but it can also be seen as a bug in cases where a version for Yosemite does not exist.

[rolandwalker]

It's a bug. The depends_on doesn't get tested until install time.

One immediate answer is that we should allow a special value such as url :unknown which will ensure that the Cask "compiles" but allow a more graceful failure later in the process.

A longer term answer is a variant syntax instead of if.

EDIT: the relevant open issue on :unknown is #5248

[rolandwalker]

For development purposes, it would also be nice to have a convenient way of overriding the OS X release, architecture, etc, at the CLI.

[rolandwalker]

This is improved by #7935 in that the failing test will give a descriptive error such as "url is required".

The missing piece is to accept :unknown as a value for all required stanzas (or perhaps false). So I'm closing in favor of existing #5248.