This had to be added in #1750 to work around special-casing for tabs
generated with Homebrew versions < 1.1.6. Now that 1.1.6 is the current
version, we can remove this hack.

This should apply only for new formulae but we should start gradually
phasing it out for older ones too.

Don't use Homebrew/versions in a test and remove them both from the
OFFICIAL_TAPS list (i.e. `brew search`).

Imports from homebrew/versions are migrated from that tap and then
renamed immediately when they hit homebrew/core. This did not trigger
our previous rename detection so address these to improve the output and
handle migration correctly.

When reproducing issues with software that hasn’t been bottled yet on
your version of macOS it can sometimes be helpful to use `or_later`
bottle functionality i.e. just use the bottle for the latest version of
macOS available. This maps well to the existing `--force-bottle`
argument so it will now act as if the latest bottle has a `or_later`
ending.

Closes #1525. (See there for a motivation for this change.)

It should accept arguments.

Fixes https://github.com/Homebrew/homebrew-core/issues/8362

In #1497 I switched from Keg#to_formula for comparing kegs to formulae
to comparing the name and tap in the keg's tab to the name and tap of
the formula.

However, this fails to match if the name and tap of the formula have
changed since the keg was installed, so it's clearly better to use
Keg#to_formula where possible, and fall back to the information in the
tab when #to_formula can't be used.

If you specify a formula more than once or it exists in the Cellar with
an alias name and the main name (e.g. `qt` and `qt5`) you can see the
same formula showing up more than once. Instead, resolve these output
lists of formulae such that they are unique based on their `name`. This
doesn't use `full_name` as it's `name` that's use for the `Cellar`.

Return `opt_prefix` if it exists and `prefix` is not called from within
the same formula's `install` or `post_install` methods. Otherwise, fall
back to the existing functionality.

This avoids the need to use `opt_prefix` etc. everywhere and generally
means we don't expose an implementation detail (i.e. the full Cellar
path) to dependents that have a habit of hard-coding it.

This is a proper fix to the problem addressed by #1510.

The problem arises when f_kegs is nil, which can happen if the name and
tap used to install a keg don't match the name and tap currently
associated with its formula (i.e. if it's been renamed or moved).

This reverts commit d7e72899.

See https://github.com/Homebrew/brew/pull/1752#discussion_r94257147

See https://github.com/Homebrew/brew/pull/1750#discussion_r94243825 for
discussion.

Removes Tab#reliable_runtime_dependencies? in favour of returning nil
from Tab#runtime_dependencies if the list is unreliable.

Because Homebrew 1.1.6 hasn't been tagged yet, tabs created in tests
aren't created with a homebrew_version that marks the
runtime_dependencies in the Tab as reliable, so there are some tests
that fail. To work around this, I've had to add a line to some tests
that explicitly overrides the homebrew_version in the Tab. This is
really ugly though, so they should be removed as soon as possible after
1.1.6 is released.

These should have been deprecated long ago but we didn’t really have
the necessary framework to do so.

This will use Curl’s default user agent to reduce homepage errors and
provides a function that can be used for other audits to perform
similar tests on URLs.

Otherwise an uncommitted formula can trigger an invalid `brew audit`
result.

Fixes #1731.

Fixes #1524.

This method isn't used any more

It didn't occur to me that this would work, but it does! Magic.

The example command given in the dependency errors/warnings previously
comma-seperated the kegs, which was incorrect syntax. This fixes that.

Previously, this only included a subset of all the kegs the user was
trying to uninstall. With this change, all named formulae/kegs will be
included in the example command.

Fixes #1554.

Require `HOMEBREW_CHECK_RECURSIVE_VERSION_DEPENDENCIES` to be specified
(which will be by `brew test-bot`) to avoid this being inflicted on
end-users unnecessarily.

This has been tested by `brew test-bot` since March and there’s been no
issues so let’s turn it on by default.