Make `Library/Homebrew` the new root now that *all* implementation files
are in this directory. Update filters/groups accordingly.

Note that paths in filters/groups are not anchored at the root and are
always matched against the full path. Our rules are effectively anchored
because they always include the `/Homebrew/` path component.

Provides feature parity between the block and non-block forms of
inreplace by creating a four-argument version of the non-block form,
where the fourth argument is an optional Boolean value, defaulting to
true, which specifies whether a failed inreplace should cause an
InreplaceError error to be raised. The fourth argument is passed along
to StringInreplaceExtension#gsub!, which already supports an optional
audit_result argument.

This resolves the Catch-22 that single replacements aren't permissible
in the block form (in that they now cause `brew audit` to complain), but
the audit_result argument is not available in the non-block form.

Closes #552.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

Since we are loading options as Formula#build from tab, we will have to explicitly read
options from ARGV as well.

Fixes #3066.

Closes #537.

Signed-off-by: Xu Cheng <xucheng@me.com>

We already loaded tab in ARGV.resolved_formulae or Formulary.from_rack

We already loaded build options in ARGV.resolved_formulae for test and
postinstall

BuiltOptions#without? already handles the option_names for dependencies.

Also check disabled recommended deps.

Closes #524.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Fixes https://github.com/Homebrew/homebrew-core/issues/3067.

Aside from being bad style, this also assigns to an unused variable.

If rubocop invocation from brew audit exits with nil exitstatus,
brew audit fails with 'undefined method `>' for nil:NilClass'.

Also prevent the commit of formula's HeadVersion from passing to the resource. 

This is a fix of #531

On systems prior to 10.9, formulae that use CVS as a download source
check whether the installed Xcode already provides CVS to avoid adding
a dependency on the `cvs` formula. Unfortunately, if no Xcode is
installed the check fails with

  undefined method `<' for nil:NilClass

causing the formula to become unloadable. This in turn causes some taps
to be untappable since #396 added the `readall` check on `tap`.

Closes #508.

Closes #529.

Signed-off-by: Xu Cheng <xucheng@me.com>

This prevents a link conflict during `brew upgrade` causing opt link
stuck to old version. At this point, users will have to run `brew switch`
to fix it.

Closes #533.

Signed-off-by: Xu Cheng <xucheng@me.com>

Switch to HOMEBREW_LIBRARY since HOMEBREW_LIBRARY_PATH already includes
"/Homebrew" and HOMEBREW_LIBRARY is less confusing.

Closes #530.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

Closes #478.

Signed-off-by: Xu Cheng <xucheng@me.com>

Substitue each Version.new and HeadVersion.new with Version.create
to unify Version and HeadVersion instantiation among core code.

Note that this does not relate to Mac::OS::Version class.

* Test `Formula#update_head_version`
* Test `Formula#latest_head_prefix`

We're moving more stuff to Homebrew Cask which is better maintained and run.

Closes https://github.com/Homebrew/brew/issues/519
Closes https://github.com/Homebrew/homebrew-core/issues/3029

Move some stuff formerly in `Library/ENV` around:
- Move `Library/ENV/$XCODE_VERSION` to `Library/Homebrew/env/super` as they are
  all superenv wrappers and all symlinks to the same version. We never needed
  the "separate shims for separate versions" functionality and it just adds
  confusion.
- Move `Library/ENV/pkgconfig` to `Library/Homebrew/env/pkgconfig` to get more
  things under `Library/Homebrew`
- Move `Library/ENV/scm` to `Library/scm` as these wrappers are not actually
  used by or related to superenv (or stdenv) in any way.

Users may have ~/.curlrc file to include options like proxies.
However, since we overwrite HOME environment variable during the build
and test, curl won't be able to find it.

This commit solves this issue by using CURL_HOME environment variable,
which will be pointed to the original HOME path.

From `curl(1)`:
> 1) curl tries to find the "home dir": It first  checks  for  the
     CURL_HOME and then the HOME environment variables. Failing that,
     it uses getpwuid() on Unix-like systems (which returns the  home
     dir  given the current user in your system). On Windows, it then
     checks for the APPDATA variable, or as a last resort the '%USER-
     PROFILE%\Application Data'.