Bootstrap environment-modules

Renames the existing bootstrap command to 'clone'. Repurposes
'spack bootstrap' to install packages that are useful to the
operation of Spack (for now this is just environment-modules).
For bash and ksh users running setup-env.sh, if a Spack-installed
instance of environment-modules is detected and environment modules
and dotkit are not externally available, Spack will define the 
'module' command in the user's shell to use the environment-modules
built by Spack.

share/spack/setup-env.sh

@@ -27,7 +27,9 @@
 #
 # This file is part of Spack and sets up the spack environment for
 # bash and zsh.  This includes dotkit support, module support, and
-# it also puts spack in your path.  Source it like this:
+# it also puts spack in your path.  The script also checks that
+# at least module support exists, and provides suggestions if it
+# doesn't. Source it like this:
 #
 #    . /path/to/spack/share/spack/setup-env.sh
 #
@@ -189,19 +191,68 @@ if [ -z "$_sp_source_file" ]; then
 fi
 
 #
-# Set up modules and dotkit search paths in the user environment
+# Find root directory and add bin to path.
 #
 _sp_share_dir=$(cd "$(dirname $_sp_source_file)" && pwd)
 _sp_prefix=$(cd "$(dirname $(dirname $_sp_share_dir))" && pwd)
 _spack_pathadd PATH       "${_sp_prefix%/}/bin"
+export SPACK_ROOT=${_sp_prefix}
 
+#
+# Determine which shell is being used
+#
+function _spack_determine_shell() {
+	ps -p $$ | tail -n 1 | awk '{print $4}' | xargs basename
+}
+export SPACK_SHELL=$(_spack_determine_shell)
+
+#
+# Check whether a shell function of the given name is defined
+#
+function _spack_fn_exists() {
+	type $1 2>&1 | grep -q 'shell function'
+}
+
+need_module="no"
+if [ ! $(_spack_fn_exists use) ] && [ ! $(_spack_fn_exists module) ]; then
+	need_module="yes"
+fi;
+
+#
+# build and make available environment-modules
+#
+if [ "${need_module}" = "yes" ]; then
+    #check if environment-modules~X is installed
+    module_prefix="$(spack location -i "environment-modules" 2>&1 || echo "not_installed")"
+    module_prefix=$(echo ${module_prefix} | tail -n 1)
+    if [ "${module_prefix}" != "not_installed" ]; then
+        #activate it!
+        export MODULE_PREFIX=${module_prefix}
+        _spack_pathadd PATH "${MODULE_PREFIX}/Modules/bin"
+        module() { eval `${MODULE_PREFIX}/Modules/bin/modulecmd ${SPACK_SHELL} $*`; }
+        echo "INFO: Using spack managed module system."
+    else
+        echo "WARNING: A method for managing modules does not currently exist."
+        echo ""
+        echo "To resolve this you may either:"
+        echo "1. Allow spack to handle this by running 'spack boostrap'"
+        echo "   and sourcing this script again."
+        echo "2. Install and activate a supported module managment engine manually"
+        echo "   Supported engines include: environment-modules and lmod"
+    fi;
+else
+    echo "INFO: Using system available module system."
+fi;
+
+#
+# Set up modules and dotkit search paths in the user environment
+#
 _sp_sys_type=$(spack-python -c 'print(spack.architecture.sys_type())')
 _sp_dotkit_root=$(spack-python -c "print(spack.util.path.canonicalize_path(spack.config.get_config('config').get('module_roots', {}).get('dotkit')))")
 _sp_tcl_root=$(spack-python -c "print(spack.util.path.canonicalize_path(spack.config.get_config('config').get('module_roots', {}).get('tcl')))")
 _spack_pathadd DK_NODE    "${_sp_dotkit_root%/}/$_sp_sys_type"
 _spack_pathadd MODULEPATH "${_sp_tcl_root%/}/$_sp_sys_type"
 
-#
 # Add programmable tab completion for Bash
 #
 if [ -n "${BASH_VERSION:-}" ]; then