brew install -v fish log

$ brew install -v fish
==> Downloading https://github.com/fish-shell/fish-shell/releases/download/2.1.1/fish-2.1.1.tar.gz
Already downloaded: /Library/Caches/Homebrew/fish-2.1.1.tar.gz
==> Verifying fish-2.1.1.tar.gz checksum
tar xf /Library/Caches/Homebrew/fish-2.1.1.tar.gz
==> ./configure --prefix=/usr/local/Cellar/fish/2.1.1 SED=/usr/bin/sed
checking if autoconf needs to be run... no
checking if autoheader needs to be run... no
checking whether the C++ compiler works... yes
checking for C++ compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C++ compiler... yes
checking whether clang++ accepts -g... yes
checking for a BSD-compatible install... /usr/bin/install -c
CXXFLAGS: -g -O2
checking for /usr/pkg/include include directory... no
checking for /usr/pkg/lib library directory... no
checking for /usr/pkg/bin command directory... no
checking for /sw/include include directory... no
checking for /sw/lib library directory... no
checking for /sw/bin command directory... no
checking for /opt/include include directory... no
checking for /opt/lib library directory... no
checking for /opt/bin command directory... no
checking for /opt/local/include include directory... yes
checking for /opt/local/lib library directory... yes
checking for /opt/local/bin command directory... yes
checking for /usr/local/include include directory... yes
checking for /usr/local/lib library directory... yes
checking for /usr/local/bin command directory... yes
checking for msgfmt... no
checking for doxygen... no
checking if we are compiling against glibc... no
checking build system type... x86_64-apple-darwin14.0.0
checking host system type... x86_64-apple-darwin14.0.0
checking target system type... x86_64-apple-darwin14.0.0
checking if we are under Solaris... no
checking if we are using non varargs tparm.... no
checking if we are under BSD... no
checking for /proc/self/stat... no
checking for library containing connect... none required
checking for library containing nanosleep... none required
checking for library containing pthread_create... none required
checking for library containing setupterm... -lncurses
checking for library containing nan... none required
checking for library containing iconv_open... no
checking for library containing libiconv_open... no
configure: error: Could not find an iconv implementation, needed to build fish
==> Configuration
HOMEBREW_VERSION: 0.9.5
HEAD: f03104755df8cbfb720254bd88ac7594a3837d36
CPU: quad-core 64-bit haswell
OS X: 10.10.1-x86_64
CLT: 6.1.0.0.1.1413057044
X11: N/A
==> ENV
HOMEBREW_CC: clang
HOMEBREW_CXX: clang++
MAKEFLAGS: -j4
CMAKE_PREFIX_PATH: /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_LIBDIR: /usr/lib/pkgconfig:/usr/local/Library/ENV/pkgconfig/10.10
ACLOCAL_PATH: /usr/local/share/aclocal
PATH: /usr/local/Library/ENV/4.3:/usr/bin:/bin:/usr/sbin:/sbin

Error: fish 2.1.1 did not build
Logs:
     /Users/kmisiunas/Library/Logs/Homebrew/fish/01.configure
     /Users/kmisiunas/Library/Logs/Homebrew/fish/01.configure.cc
     /Users/kmisiunas/Library/Logs/Homebrew/fish/config.log




$brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry and just ignore them. Thanks!

Warning: "config" scripts exist outside your system or Homebrew directories.
`./configure` scripts often look for *-config scripts to determine if
software packages are installed, and what additional flags to use when
compiling and linking.

Having additional scripts in your path can confuse software installed via
Homebrew if the config script overrides a system or Homebrew provided
script of the same name. We found the following "config" scripts:

  /opt/local/bin/gpg-error-config
  /opt/local/bin/libgcrypt-config