Closes Homebrew/homebrew#19227.

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

See 05a456c231dc6da7cb0f7c70cb21feaf9a0d803c; same story.

This is an internal method, but is called a bunch of times in
performance-critical codepaths, and is ultra slow because the constant
is interpoplated into the Regexp each time the method is called.

Alas, this has been fixed in Ruby 1.9+.

A FormulaPin object is created every time Formula is instantiated, so
don't do filesystem operations or Pathname concatenation eagerly.

This method (well, really, #join) is *twice* as slow as simple
concatenation, and shouldn't really be used at all in non-Formula code.

Benchmark.bm do |b|
  b.report("before") do
    100_000.times { /(\.#{MacOS.cat}\.bottle\.(\d+\.)?tar\.gz)$/ }
  end
  b.report("after ") do
    100_000.times { /(\.#{MacOS.cat}\.bottle\.(\d+\.)?tar\.gz)$/o }
  end
end
            user     system      total        real
before 35.400000   0.140000  35.540000 ( 35.619674)
after   0.020000   0.000000   0.020000 (  0.016662)

Closes Homebrew/homebrew#19192.

Closes Homebrew/homebrew#18835.

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

This behavior is now tested at more appropriate levels in
test_software_spec, test_formula_spec_selection, and
test_formula_validation.

These tests document the relative precedence of the stable, bottle,
devel, and head specifications, and the conditions that can influence
which is selected (e.g. command-line flags).

It seems only natural that this should be possible, or at the very
least, it should not result in calling methods on nil.

The initializer for Formula does a number of validations, but it does
them in a weird order, and some attributes aren't validated under
certain circumstances. This became even more of a mess when most
software package attributes were moved into the SoftwareSpec class.

This commit removes the last vestiges of storing these attributes as
instance variables. In particular, it eliminates #set_instance_variable
and #validate_variable, replacing them with methods that operate on
SoftwareSpec instances, and generate more useful errors.

Doing these validations unconditionally in the initializer means we bail
out much earlier if the formula has invalid attributes or is not fully
specified, and no longer need to validate in #prefix.

Technically we don't need to validate in #brew either, but we continue
to do so anyway as a safety measure, and because we cannot enforce calls
to super in subclasses.

And by extension, `cleanup`.

Fixes Homebrew/homebrew#18658.

Closes Homebrew/homebrew#19083.

It was pointed out that 'raring' is a rare word can be confusing to
non-native speakers.

Closes Homebrew/homebrew#18659, see that for details.

Also include a writability check for lib.

Closes Homebrew/homebrew#18571.

Closes Homebrew/homebrew#19050.

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

brew versions is hardcoded to cd to HOMEBREW_REPOSITORY before running
git, and as such fails to report previous versions for any formulae
from a tapped repository.

Add two new private methods repository and entry_name to replace the
hardcoded HOMEBREW_REPOSITORY and formula path, and brew versions
work for both builtin and tapped formulae.

Closes Homebrew/homebrew#12356.
Closes Homebrew/homebrew#19069.

Reported-by: Misty De Meo <mistydemeo@gmail.com>
Suggested-by: Jack Nagel <jacknagel@gmail.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Closes Homebrew/homebrew#19106.

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

Closes Homebrew/homebrew#19113.

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

Most of the behavior tested here is now tested elsewhere. Move the
remaining useful tests to better places.

Fixes Homebrew/homebrew#19107.