diff --git a/bootstrap.sh b/bootstrap.sh
index 639fd82b..5e9d4041 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -1,5 +1,12 @@
 #!/usr/bin/env bash
 
-./scripts/update_eigen.sh eigen-3.2.9.tar.bz2
+EIGEN_URL='http://bitbucket.org/eigen/eigen/get/3.2.9.tar.bz2'
+
+echo "-- deploying Eigen source..."
+wget ${EIGEN_URL}
+./scripts/update_eigen.sh `basename ${EIGEN_URL}`
+rm `basename ${EIGEN_URL}`
+echo '-- generating Make.inc files...'
 ./scripts/filelist
+echo '-- generating configure script...'
 autoreconf -fvi
diff --git a/configure.ac b/configure.ac
index 997df641..905a665b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -79,7 +79,8 @@ AC_CHECK_LIB([gmp],[__gmpf_init],
                  [AC_MSG_ERROR([MPFR library not found])])]
              [AC_DEFINE([HAVE_LIBGMP], [1], [Define to 1 if you have the `GMP' library (-lgmp).])]
              [have_gmp=true]
-             [LIBS="$LIBS -lgmp"])
+             [LIBS="$LIBS -lgmp"],
+             [AC_MSG_WARN([**** GMP library not found, Grid can still compile but RHMC will not work ****])])
 
 if test "${ac_LAPACK}x" != "nox"; then
     AC_CHECK_LIB([lapack],[LAPACKE_sbdsdc],[],
@@ -118,7 +119,7 @@ case ${ax_cv_cxx_compiler_vendor} in
         AC_DEFINE([GENERIC_VEC],[1],[generic vector code])
         SIMD_FLAGS='';;
       *)
-        AC_MSG_ERROR(["SIMD option ${ac_SIMD} not supported by the GCC/Clang"]);;
+        AC_MSG_ERROR(["SIMD option ${ac_SIMD} not supported by the GCC/Clang compiler"]);;
     esac;;
   intel)
     case ${ac_SIMD} in
@@ -175,13 +176,13 @@ case ${ac_PRECISION} in
 esac
 
 ############### communication type selection
-AC_ARG_ENABLE([comms],[AC_HELP_STRING([--enable-comms=none|mpi],[Select communications])],[ac_COMMS=${enable_comms}],[ac_COMMS=none])
+AC_ARG_ENABLE([comms],[AC_HELP_STRING([--enable-comms=none|mpi|mpi-auto|shmem],[Select communications])],[ac_COMMS=${enable_comms}],[ac_COMMS=none])
 
 case ${ac_COMMS} in
      none)
        AC_DEFINE([GRID_COMMS_NONE],[1],[GRID_COMMS_NONE] )
      ;;
-     mpi)
+     mpi-auto)
        AC_DEFINE([GRID_COMMS_MPI],[1],[GRID_COMMS_MPI] )
        LX_FIND_MPI
        if test "x$have_CXX_mpi" = 'xno'; then AC_MSG_ERROR(["MPI not found"]); fi
@@ -190,6 +191,9 @@ case ${ac_COMMS} in
        AM_LDFLAGS="`echo $MPI_CXXLDFLAGS | sed -E 's/-l@<:@^ @:>@+//g'` $AM_LDFLAGS"
        LIBS="`echo $MPI_CXXLDFLAGS | sed -E 's/-L@<:@^ @:>@+//g'` $LIBS"
      ;;
+     mpi)
+       AC_DEFINE([GRID_COMMS_MPI],[1],[GRID_COMMS_MPI] )
+     ;;
      shmem)
        AC_DEFINE([GRID_COMMS_SHMEM],[1],[GRID_COMMS_SHMEM] )
      ;;
@@ -198,7 +202,7 @@ case ${ac_COMMS} in
      ;;
 esac
 AM_CONDITIONAL(BUILD_COMMS_SHMEM,[ test "X${ac_COMMS}X" == "XshmemX" ])
-AM_CONDITIONAL(BUILD_COMMS_MPI,[ test "X${ac_COMMS}X" == "XmpiX" ])
+AM_CONDITIONAL(BUILD_COMMS_MPI,[ test "X${ac_COMMS}X" == "XmpiX" || test "X${ac_COMMS}X" == "Xmpi-autoX" ])
 AM_CONDITIONAL(BUILD_COMMS_NONE,[ test "X${ac_COMMS}X" == "XnoneX" ])
 
 ############### RNG selection
diff --git a/eigen-3.2.9.tar.bz2 b/eigen-3.2.9.tar.bz2
deleted file mode 100644
index 2210a2c3..00000000
Binary files a/eigen-3.2.9.tar.bz2 and /dev/null differ
diff --git a/lib/simd/Grid_empty.h b/lib/simd/Grid_generic.h
similarity index 97%
rename from lib/simd/Grid_empty.h
rename to lib/simd/Grid_generic.h
index 70ad1748..ca0029ef 100644
--- a/lib/simd/Grid_empty.h
+++ b/lib/simd/Grid_generic.h
@@ -2,7 +2,7 @@
 
     Grid physics library, www.github.com/paboyle/Grid 
 
-    Source file: ./lib/simd/Grid_empty.h
+    Source file: ./lib/simd/Grid_generic.h
 
     Copyright (C) 2015
 
@@ -26,14 +26,6 @@ Author: neo <cossu@post.kek.jp>
     See the full license in the file "LICENSE" in the top level distribution directory
     *************************************************************************************/
     /*  END LEGAL */
-//----------------------------------------------------------------------
-/*! @file Grid_sse4.h
-  @brief Empty Optimization libraries for debugging
-
-  Using intrinsics
-*/
-// Time-stamp: <2015-06-09 14:28:02 neo>
-//----------------------------------------------------------------------
 
 namespace Grid {
 namespace Optimization {
diff --git a/lib/simd/Grid_vector_types.h b/lib/simd/Grid_vector_types.h
index 2677d174..2f2b70c8 100644
--- a/lib/simd/Grid_vector_types.h
+++ b/lib/simd/Grid_vector_types.h
@@ -39,7 +39,7 @@ directory
 #define GRID_VECTOR_TYPES
 
 #ifdef GENERIC_VEC
-#include "Grid_empty.h"
+#include "Grid_generic.h"
 #endif
 #ifdef SSE4
 #include "Grid_sse4.h"