This requires hitting the network, which makes the first invocation
slow. The results are inaccurate as it only pulls down the first page of
results. It is also prone to false-positives.

A better implementation is welcome, but in the years since I wrote this
code I can't think of a single time where I found it useful.

This commit supports "-" and "_" in names of user and repository.

Closes Homebrew/homebrew#28203.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Fixes Homebrew/homebrew#28680.

Closes Homebrew/homebrew#27311.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Closes Homebrew/homebrew#28418.

This is where people expect to find it so let's make it easier.

Closes Homebrew/homebrew#28418.

It is activated by the same mechanism as the Homebrew/versions compilers
which now check if the GCC formula uses the same, correct version.

References Homebrew/homebrew#28418.

This allows disabling this checks when e.g. pouring bottles.

`MacOS::Xcode.without_clt? && MacOS.sdk_path.nil?` should never be true.

In its earliest form, this would raise a bare RuntimeError in an effort
to have the bug reported. Later, it was changed to silently disable
superenv. But we don't want to do that. If there's a bug, or the user's
system is misconfigured, we want to know, so that we can fix the bug, or
the user can fix their system. So let's remove the condition.

Closes Homebrew/homebrew#28588.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Closes Homebrew/homebrew#28550.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>