Brew audit doesn't like that I hardcoded in clang, but building this or the previous formula always failed for me if I didn't do that or use env=std. I figured hardcoding the compiler is preferable to throwing out the Brew environment entirely.

This is where it fails for the old formula, and mine without modifying ENV.cct:
```
Pulling p1_tls from {git,"git://github.com/processone/tls"}
Cloning into 'p1_tls'...
Pulling p1_stringprep from {git,"git://github.com/processone/stringprep"}
Cloning into 'p1_stringprep'...
Pulling p1_xml from {git,"git://github.com/processone/xml"}
Cloning into 'p1_xml'...
Pulling p1_yaml from {git,"git://github.com/processone/p1_yaml"}
Cloning into 'p1_yaml'...
Pulling xmlrpc from {git,"git://github.com/rds13/xmlrpc"}
Cloning into 'xmlrpc'...
Pulling p1_zlib from {git,"git://github.com/processone/zlib"}
Cloning into 'p1_zlib'...
Pulling lager from {git,"git://github.com/basho/lager"}
Cloning into 'lager'...
Pulling p1_iconv from {git,"git://github.com/processone/eiconv"}
Cloning into 'p1_iconv'...
checking for gcc... clang
checking whether the C compiler works... no
configure: error: in `/private/tmp/ejabberd-hYz5/ejabberd-13.12/deps/p1_tls':
configure: error: C compiler cannot create executables
See `config.log' for more details
ERROR: Command ['get-deps'] failed!
make: *** [deps/.got] Error 1
==> Configuration
HOMEBREW_VERSION: 0.9.5
HEAD: b623d43a14dccff6de23d4e8653ace26be23dd98
CPU: quad-core 64-bit sandybridge
OS X: 10.9.3-x86_64
Xcode: 5.1.1
CLT: 5.1.0.0.1.1396320587
X11: 2.7.5 => /opt/X11
==> ENV
HOMEBREW_CC: clang
HOMEBREW_CXX: clang++
MAKEFLAGS: -j4
CMAKE_PREFIX_PATH: /usr/local/opt/openssl:/usr/local
CMAKE_INCLUDE_PATH: /usr/include/libxml2:/System/Library/Frameworks/OpenGL.framework/Versions/Current/Headers
CMAKE_LIBRARY_PATH: /System/Library/Frameworks/OpenGL.framework/Versions/Current/Libraries
PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig:/usr/local/opt/libpng/lib/pkgconfig:/usr/local/opt/libtiff/lib/pkgconfig:/usr/local/opt/libyaml/lib/pkgconfig
PKG_CONFIG_LIBDIR: /usr/lib/pkgconfig:/usr/local/Library/ENV/pkgconfig/10.9
HOMEBREW_BUILD_FROM_SOURCE: 1
ACLOCAL_PATH: /usr/local/share/aclocal
PATH: /usr/local/Library/ENV/4.3:/usr/local/opt/openssl/bin:/usr/local/opt/unixodbc/bin:/usr/local/opt/jpeg/bin:/usr/local/opt/libpng/bin:/usr/local/opt/libtiff/bin:/usr/local/opt/wxmac/bin:/usr/local/opt/erlang/bin:/usr/bin:/bin:/usr/sbin:/sbin

Error: ejabberd 13.12 did not build
```
So by breaking before that point and looking at *deps/p1_tls/config.log*, I determined that *Library/ENV/4.3/clang* was the problem.

```
## ----------- ##
## Core tests. ##
## ----------- ##

configure:2045: checking for gcc
configure:2072: result: clang
configure:2301: checking for C compiler version
configure:2310: clang --version >&5
/usr/local/Library/ENV/4.3/clang:241:in `archflags': private method `split' called for nil:NilClass (NoMethodError)
	from /usr/local/Library/ENV/4.3/clang:220:in `cflags'
	from /usr/local/Library/ENV/4.3/clang:102:in `args'
	from /usr/local/Library/ENV/4.3/clang:354
configure:2321: $? = 1
configure:2310: clang -v >&5
Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin13.2.0
Thread model: posix
configure:2321: $? = 0
configure:2310: clang -V >&5
/usr/local/Library/ENV/4.3/clang:241:in `archflags': private method `split' called for nil:NilClass (NoMethodError)
	from /usr/local/Library/ENV/4.3/clang:220:in `cflags'
	from /usr/local/Library/ENV/4.3/clang:102:in `args'
	from /usr/local/Library/ENV/4.3/clang:354
configure:2321: $? = 1
configure:2310: clang -qversion >&5
/usr/local/Library/ENV/4.3/clang:241:in `archflags': private method `split' called for nil:NilClass (NoMethodError)
	from /usr/local/Library/ENV/4.3/clang:220:in `cflags'
	from /usr/local/Library/ENV/4.3/clang:102:in `args'
	from /usr/local/Library/ENV/4.3/clang:354
configure:2321: $? = 1
configure:2341: checking whether the C compiler works
configure:2363: clang    conftest.c  >&5
/usr/local/Library/ENV/4.3/clang:241:in `archflags': private method `split' called for nil:NilClass (NoMethodError)
	from /usr/local/Library/ENV/4.3/clang:220:in `cflags'
	from /usr/local/Library/ENV/4.3/clang:102:in `args'
	from /usr/local/Library/ENV/4.3/clang:354
configure:2367: $? = 1
configure:2405: result: no
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "tls"
| #define PACKAGE_TARNAME "tls"
| #define PACKAGE_VERSION "0.2.0"
| #define PACKAGE_STRING "tls 0.2.0"
| #define PACKAGE_BUGREPORT ""
| #define PACKAGE_URL ""
| /* end confdefs.h.  */
| 
| int
| main ()
| {
| 
|   ;
|   return 0;
| }
configure:2410: error: in `/private/tmp/ejabberd-l9mu/ejabberd-14.05/deps/p1_tls':
configure:2412: error: C compiler cannot create executables
See `config.log' for more details
```
So it appears to me that we will either have to keep this hack, or someone will have to fix whatever's causing issue's in Homebrew's ENV.