brew install -v --HEAD ledger

gistfile1.txt

$ brew install -v --HEAD ledger
==> Installing ledger
==> Cloning https://github.com/jwiegley/ledger.git
Updating /Library/Caches/Homebrew/ledger--git
git remote set-url origin https://github.com/jwiegley/ledger.git
git fetch origin
==> Checking out branch next
git checkout origin/next
HEAD is now at 1809e63... Added a test harness error diagnostic
git checkout-index -a -f --prefix=/private/tmp/homebrew-ledger-HEAD-E6YH/
git submodule init
Submodule 'lib/utfcpp' () registered for path 'lib/utfcpp'
git submodule update
git submodule --quiet foreach --recursive git checkout-index -a -f "--prefix=/private/tmp/homebrew-ledger-HEAD-E6YH/$path/"
==> ./acprep  -j2 opt make -- --prefix=/usr/local/Cellar/ledger/HEAD
./acprep  -j2 opt make -- --prefix=/usr/local/Cellar/ledger/HEAD 
acprep: INFO: Invoking primary phase: make
acprep: INFO: Executing phase: make
acprep: INFO: Executing phase: config
acprep: INFO: Executing phase: submodule
acprep: INFO: Executing phase: autoconf
acprep: INFO: autogen.sh must be run because acprep is newer than configure
acprep: INFO: Executing phase: autogen
Preparing the ledger build system...please wait

Found GNU Autoconf version 2.68
Found GNU Automake version 1.11.3

Warning:  libtoolize does not appear to be available.  This means that
the automatic build preparation via autoreconf will probably not work.
Preparing the build by running each step individually, however, should
work and will be done automatically for you if autoreconf fails.

Fortunately, glibtoolize was found which means that your system may simply
have a non-standard or incomplete GNU Autotools install.  If you have
sufficient system access, it may be possible to quell this warning by
running:

   sudo ln -s /usr/local/bin/glibtoolize /usr/local/bin/libtoolize

Found GNU Libtool version 2.4.2

Automatically preparing build ... done

The ledger build system is now prepared.  To build here, run:
  ./configure
  make
acprep: INFO: Executing phase: gettext
acprep: INFO: Moving po/Makevars.template -> po/Makevars
acprep: INFO: Executing phase: aclocal
acprep: INFO: Executing phase: configure
acprep: INFO: System type is => Darwin
acprep: INFO: Looking for Boost in /usr/local/lib64...
acprep: INFO: Looking for Boost in /opt/local/lib64...
acprep: INFO: Looking for Boost in /sw/lib64...
acprep: INFO: Looking for Boost in /usr/lib64...
acprep: INFO: Looking for Boost in /usr/local/lib...
acprep: INFO: Found a Boost library: /usr/local/lib/libboost_regex-mt.dylib
acprep: INFO: Found a Boost suffix => -mt
acprep: INFO: Found a Boost file suffix => .dylib
acprep: INFO: Boost was found here:
acprep: INFO: Boost home path    => /usr/local
acprep: INFO: Boost include path => /usr/local/include
acprep: INFO: Boost library path => /usr/local/lib
acprep: INFO: Boost suffix       => -mt
acprep: INFO: Boost file suffix  => .dylib
acprep: INFO: Noticing include directory => /usr/local/include
acprep: INFO: Noticing include directory => /usr/local/include
acprep: INFO: Noticing library directory => /usr/local/lib
acprep: INFO: Setting up build flavor => opt
acprep: INFO: ./configure must be run because Makefile does not exist
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... ./install-sh -c -d
checking for gawk... no
checking for mawk... no
checking for nawk... no
checking for awk... awk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking for style of include used by make... GNU
checking for gcc... gcc
checking whether the C compiler works... no
configure: error: in `/private/tmp/homebrew-ledger-HEAD-E6YH':
configure: error: C compiler cannot create executables
See `config.log' for more details
acprep: ERROR: Execution failed: sh configure CPPFLAGS=-I/usr/local/Cellar/gettext/0.18.1.1/include -DNDEBUG=1 -isystem /usr/local/include -isystem /usr/local/include -isystem /System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 CFLAGS=-Os -w -pipe -march=native -Qunused-arguments -O3 CXXFLAGS=-Os -w -pipe -march=native -Qunused-arguments -Wconversion -O3 -pipe LDFLAGS=-L/usr/local/Cellar/gettext/0.18.1.1/lib -L/usr/local/lib -fpch-deps -O3 -L/usr/local/lib --with-boost-suffix=-mt --with-included-gettext --prefix=/usr/local/Cellar/ledger/HEAD
config.log was copied to /Users/yun/Library/Logs/Homebrew
==> Exit Status: 1
https://github.com/mxcl/master/blob/master/Library/Formula/ledger.rb#L31
==> Build Environment
CPU: dual-core 64-bit penryn
MacOS: 10.7.3-x86_64
Xcode: 4.3.2
CC: /usr/bin/clang
CXX: /usr/bin/clang++ => /usr/bin/clang
LD: /usr/bin/clang
CFLAGS: -Os -w -pipe -march=native -Qunused-arguments
CXXFLAGS: -Os -w -pipe -march=native -Qunused-arguments
CPPFLAGS: -I/usr/local/Cellar/gettext/0.18.1.1/include
LDFLAGS: -L/usr/local/Cellar/gettext/0.18.1.1/lib -L/usr/local/lib
MAKEFLAGS: -j2
Error: Failed executing: ./acprep  -j2 opt make -- --prefix=/usr/local/Cellar/ledger/HEAD (ledger.rb:31)
If `brew doctor' does not help diagnose the issue, please report the bug:
    https://github.com/mxcl/homebrew/wiki/reporting-bugs