Intenté reinstalar Ruby, Xcode y un montón de otras cosas porque seguí recibiendo estos extraños errores de compilador de C. En algún momento todos mis rubíes fueron desinstalados, así que volví al principio ...

rvm get head && rvm reload
rvm install 1.9.3

Obtuve el siguiente error:

No binary rubies available for: downloads/ruby-1.9.3-p327.
Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies.
Installing Ruby from source to: /Users/mgriffel/.rvm/rubies/ruby-1.9.3-p327, this may take a while depending on your cpu(s)...
ruby-1.9.3-p327 - #downloading ruby-1.9.3-p327, this may take a while depending on your connection...
ruby-1.9.3-p327 - #extracted to /Users/mgriffel/.rvm/src/ruby-1.9.3-p327 (already extracted)
ruby-1.9.3-p327 - #configuring
Error running 'env LDFLAGS=-L/opt/sm/pkg/active/lib CFLAGS=-I/opt/sm/pkg/active/include CPATH=/opt/sm/pkg/active/include ./configure --enable-shared --disable-install-doc --prefix=/Users/mgriffel/.rvm/rubies/ruby-1.9.3-p327 --with-opt-dir=/Users/mgriffel/.rvm/usr', please read /Users/mgriffel/.rvm/log/ruby-1.9.3-p327/configure.log
There has been an error while running configure. Halting the installation.

Enconfigurar.log Veo:

[2012-11-14 13:21:54] env LDFLAGS=-L/opt/sm/pkg/active/lib CFLAGS=-I/opt/sm/pkg/active/include CPATH=/opt/sm/pkg/active/include ./configure --enable-shared --disable-install-doc --prefix=/Users/mgriffel/.rvm/rubies/ruby-1.9.3-p327 --with-opt-dir=/Users/mgriffel/.rvm/usr
checking build system type... x86_64-apple-darwin12.2.0
checking host system type... x86_64-apple-darwin12.2.0
checking target system type... x86_64-apple-darwin12.2.0
checking whether the C compiler works... no
configure: error: in `/Users/mgriffel/.rvm/src/ruby-1.9.3-p327':
configure: error: C compiler cannot create executables
See `config.log' for more details

Y enconfig.log Veo:

This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by configure, which was
generated by GNU Autoconf 2.68.  Invocation command line was

  $ ./configure --enable-shared --disable-install-doc --prefix=/Users/mgriffel/.rvm/rubies/ruby-1.9.3-p327 --with-opt-dir=/Users/mgriffel/.rvm/usr

## --------- ##
## Platform. ##
## --------- ##

hostname = Mattans-MacBook-Air.local
uname -m = x86_64
uname -r = 12.2.0
uname -s = Darwin
uname -v = Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64

/usr/bin/uname -p = i386
/bin/uname -X     = unknown

/bin/arch              = unknown
/usr/bin/arch -k       = unknown
/usr/convex/getsysinfo = unknown
/usr/bin/hostinfo      = Mach kernel version:
     Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64
Kernel configured for up to 4 processors.
2 processors are physically available.
4 processors are logically available.
Processor type: i486 (Intel 80486)
Processors active: 0 1 2 3
Primary memory available: 4.00 gigabytes
Default processor set: 144 tasks, 704 threads, 4 processors
Load average: 2.79, Mach factor: 1.19
/bin/machine           = unknown
/usr/bin/oslevel       = unknown
/bin/universe          = unknown

PATH: /Users/mgriffel/.rvm/usr/bin
PATH: /Users/mgriffel/.rvm/gems/ruby-1.9.3-p194@rails328/bin
PATH: /Users/mgriffel/.rvm/gems/ruby-1.9.3-p194@global/bin
PATH: /Users/mgriffel/.rvm/rubies/ruby-1.9.3-p194/bin
PATH: /Users/mgriffel/.rvm/bin
PATH: /opt/local/bin
PATH: /opt/local/sbin
PATH: /usr/local/bin
PATH: /usr/local/sbin
PATH: /usr/local/mysql/bin
PATH: /usr/bin
PATH: /bin
PATH: /usr/sbin
PATH: /sbin
PATH: /opt/sm/bin
PATH: /opt/sm/pkg/active/bin
PATH: /opt/sm/pkg/active/sbin


## ----------- ##
## Core tests. ##
## ----------- ##

configure:2769: checking build system type
configure:2783: result: x86_64-apple-darwin12.2.0
configure:2851: checking host system type
configure:2864: result: x86_64-apple-darwin12.2.0
configure:2884: checking target system type
configure:2897: result: x86_64-apple-darwin12.2.0
configure:3378: checking for C compiler version
configure:3387: /opt/local/bin/gcc-apple-4.2 --version >&5
i686-apple-darwin12-gcc-apple-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5666) (dot 3) (MacPorts apple-gcc42 5666.3_9)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

configure:3398: $? = 0
configure:3387: /opt/local/bin/gcc-apple-4.2 -v >&5
Using built-in specs.
Target: i686-apple-darwin12
Configured with: /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_apple-gcc42/apple-gcc42/work/objroot/src/configure --disable-checking --prefix=/opt/local --mandir=/opt/local/share/man --enable-languages=c,c++,objc,obj-c++ --libexecdir=/opt/local/libexec/apple-gcc42 --libdir=/opt/local/lib/apple-gcc42 --includedir=/opt/local/include/apple-gcc42 --program-suffix=-apple-4.2 --with-system-zlib --disable-nls --with-slibdir=/usr/lib --build=x86_64-apple-darwin12 --enable-werror-always --program-prefix=i686-apple-darwin12- --host=x86_64-apple-darwin12 --target=i686-apple-darwin12 --with-gxx-include-dir=/usr/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Apple Inc. build 5666) (dot 3) (MacPorts apple-gcc42 5666.3_9)
configure:3398: $? = 0
configure:3387: /opt/local/bin/gcc-apple-4.2 -V >&5
gcc-apple-4.2: argument to `-V' is missing
configure:3398: $? = 1
configure:3387: /opt/local/bin/gcc-apple-4.2 -qversion >&5
i686-apple-darwin12-gcc-apple-4.2.1: no input files
configure:3398: $? = 1
configure:3418: checking whether the C compiler works
configure:3440: /opt/local/bin/gcc-apple-4.2   -L/opt/sm/pkg/active/lib CFLAGS=-I/opt/sm/pkg/active/include CPATH=/opt/sm/pkg/active/include conftest.c  >&5
i686-apple-darwin12-gcc-apple-4.2.1: CFLAGS=-I/opt/sm/pkg/active/include: No such file or directory
i686-apple-darwin12-gcc-apple-4.2.1: CPATH=/opt/sm/pkg/active/include: No such file or directory
configure:3444: $? = 1
configure:3482: result: no
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME ""
| #define PACKAGE_TARNAME ""
| #define PACKAGE_VERSION ""
| #define PACKAGE_STRING ""
| #define PACKAGE_BUGREPORT ""
| #define PACKAGE_URL ""
| #define CANONICALIZATION_FOR_MATHN 1
| /* end confdefs.h.  */
| 
| int
| main ()
| {
| 
|   ;
|   return 0;
| }
configure:3487: error: in `/Users/mgriffel/.rvm/src/ruby-1.9.3-p327':
configure:3489: error: C compiler cannot create executables
See `config.log' for more details

## ---------------- ##
## Cache variables. ##
## ---------------- ##

ac_cv_build=x86_64-apple-darwin12.2.0
ac_cv_env_CCC_set=
ac_cv_env_CCC_value=
ac_cv_env_CC_set=set
ac_cv_env_CC_value=/opt/local/bin/gcc-apple-4.2
ac_cv_env_CFLAGS_set=
ac_cv_env_CFLAGS_value=
ac_cv_env_CPPFLAGS_set=
ac_cv_env_CPPFLAGS_value=
ac_cv_env_CPP_set=
ac_cv_env_CPP_value=
ac_cv_env_CXXFLAGS_set=
ac_cv_env_CXXFLAGS_value=
ac_cv_env_CXX_set=
ac_cv_env_CXX_value=
ac_cv_env_LDFLAGS_set=set
ac_cv_env_LDFLAGS_value='-L/opt/sm/pkg/active/lib CFLAGS=-I/opt/sm/pkg/active/include CPATH=/opt/sm/pkg/active/include'
ac_cv_env_LIBS_set=
ac_cv_env_LIBS_value=
ac_cv_env_build_alias_set=
ac_cv_env_build_alias_value=
ac_cv_env_host_alias_set=
ac_cv_env_host_alias_value=
ac_cv_env_target_alias_set=
ac_cv_env_target_alias_value=
ac_cv_host=x86_64-apple-darwin12.2.0
ac_cv_prog_CC=/opt/local/bin/gcc-apple-4.2
ac_cv_target=x86_64-apple-darwin12.2.0

## ----------------- ##
## Output variables. ##
## ----------------- ##

ALLOCA=''
AR=''
ARCHFILE=''
ARCH_FLAG=''
AS=''
ASFLAGS=''
BASERUBY='echo executable host ruby is required.  use --with-baseruby option.; false'
BUILTIN_ENCOBJS=''
BUILTIN_TRANSOBJS=''
BUILTIN_TRANSSRCS=''
CAPITARGET=''
CC='/opt/local/bin/gcc-apple-4.2'
CCDLFLAGS=''
CFLAGS=''
CHDIR=''
COMMON_HEADERS=''
COMMON_LIBS=''
COMMON_MACROS=''
COUTFLAG=''
CP=''
CPP=''
CPPFLAGS=''
CPPOUTFILE=''
CXX=''
CXXFLAGS=''
DEFS=''
DLDFLAGS=''
DLDLIBS=''
DLEXT2=''
DLEXT=''
DLLWRAP=''
DOT=''
DOXYGEN=''
ECHO_C='\c'
ECHO_N=''
ECHO_T=''
EGREP=''
ENABLE_SHARED=''
EXECUTABLE_EXTS=''
EXEEXT=''
EXPORT_PREFIX=''
EXTOUT=''
EXTSTATIC=''
GCC=''
GNU_LD=''
GREP=''
INSTALLDOC=''
INSTALL_DATA=''
INSTALL_PROGRAM=''
INSTALL_SCRIPT=''
LDFLAGS='-L/opt/sm/pkg/active/lib CFLAGS=-I/opt/sm/pkg/active/include CPATH=/opt/sm/pkg/active/include'
LDSHARED=''
LDSHAREDXX=''
LIBEXT=''
LIBOBJS=''
LIBPATHENV=''
LIBPATHFLAG=''
LIBRUBY=''
LIBRUBYARG=''
LIBRUBYARG_SHARED=''
LIBRUBYARG_STATIC=''
LIBRUBY_A=''
LIBRUBY_ALIASES=''
LIBRUBY_DLDFLAGS=''
LIBRUBY_LDSHARED=''
LIBRUBY_RELATIVE=''
LIBRUBY_SO=''
LIBS=''
LINK_SO=''
LN_S=''
LTLIBOBJS=''
MAINLIBS=''
MAJOR='1'
MAKEDIRS=''
MAKEFILES=''
MANTYPE=''
MINIOBJS=''
MINIRUBY=''
MINOR='9'
MKDIR_P=''
NM=''
NROFF=''
NULLCMD=''
OBJCOPY=''
OBJDUMP=''
OBJEXT=''
OUTFLAG=''
PACKAGE=''
PACKAGE_BUGREPORT=''
PACKAGE_NAME=''
PACKAGE_STRING=''
PACKAGE_TARNAME=''
PACKAGE_URL=''
PACKAGE_VERSION=''
PATH_SEPARATOR=':'
PKG_CONFIG=''
PLATFORM_DIR=''
PREP=''
RANLIB=''
RDOCTARGET=''
RI_BASE_NAME=''
RM=''
RMALL=''
RMDIR=''
RMDIRS=''
RPATHFLAG=''
RUBYW_BASE_NAME='rubyw'
RUBYW_INSTALL_NAME=''
RUBY_BASE_NAME='ruby'
RUBY_INSTALL_NAME=''
RUBY_PROGRAM_VERSION='1.9.3'
RUBY_RELEASE_DATE='2012-11-10'
RUBY_SO_NAME=''
RUNRUBY=''
SET_MAKE=''
SHELL='/bin/sh'
SOLIBS=''
STATIC=''
STRIP=''
SYMBOL_PREFIX=''
TEENY='1'
TEST_RUNNABLE=''
THREAD_MODEL=''
TRY_LINK=''
UNIVERSAL_ARCHNAMES=''
UNIVERSAL_INTS=''
USE_RUBYGEMS=''
WERRORFLAG=''
WINDRES=''
XCFLAGS=''
XLDFLAGS=''
XRUBY=''
XRUBY_LIBDIR=''
XRUBY_RUBYHDRDIR=''
XRUBY_RUBYLIBDIR=''
ac_ct_CC=''
ac_ct_CXX=''
ac_ct_OBJCOPY=''
ac_ct_OBJDUMP=''
arch=''
bindir='${exec_prefix}/bin'
build='x86_64-apple-darwin12.2.0'
build_alias=''
build_cpu='x86_64'
build_os='darwin12.2.0'
build_vendor='apple'
cflags=' ${optflags} ${debugflags} ${warnflags}'
configure_args=''
cppflags=''
cxxflags=' ${optflags} ${debugflags} ${warnflags}'
datadir='${datarootdir}'
datarootdir='${prefix}/share'
debugflags=''
docdir='${datarootdir}/doc/${PACKAGE}'
dvidir='${docdir}'
exec=''
exec_prefix='NONE'
host='x86_64-apple-darwin12.2.0'
host_alias=''
host_cpu='x86_64'
host_os='darwin12.2.0'
host_vendor='apple'
htmldir='${docdir}'
includedir='${prefix}/include'
infodir='${datarootdir}/info'
libdir='${exec_prefix}/lib'
libexecdir='${exec_prefix}/libexec'
localedir='${datarootdir}/locale'
localstatedir='${prefix}/var'
mandir='${datarootdir}/man'
oldincludedir='/usr/include'
optflags=''
pdfdir='${docdir}'
prefix='/Users/mgriffel/.rvm/rubies/ruby-1.9.3-p327'
program_transform_name='s&^&&'
psdir='${docdir}'
ridir=''
ruby_pc=''
ruby_version=''
rubyhdrdir=''
rubylibprefix=''
rubyw_install_name=''
sbindir='${exec_prefix}/sbin'
setup=''
sharedstatedir='${prefix}/com'
sitearch=''
sitedir=''
sitehdrdir=''
sysconfdir='${prefix}/etc'
target='x86_64-apple-darwin12.2.0'
target_alias=''
target_cpu='x86_64'
target_os='darwin12.2.0'
target_vendor='apple'
try_header=''
vendordir=''
vendorhdrdir=''
warnflags=''

## ----------- ##
## confdefs.h. ##
## ----------- ##

/* confdefs.h */
#define PACKAGE_NAME ""
#define PACKAGE_TARNAME ""
#define PACKAGE_VERSION ""
#define PACKAGE_STRING ""
#define PACKAGE_BUGREPORT ""
#define PACKAGE_URL ""
#define CANONICALIZATION_FOR_MATHN 1

configure: exit 77

No puedo, por mi vida, averiguar qué es lo que está mal y he estado atrapado aquí durante días. Cualquier ayuda aquí sería muy apreciada.

Nota: Tengo instalada la última versión de Xcode y CLT.