Add back help placeholder for "spack load" (#6127)

Fixes #6126

#3183 removed the print_help function from the "modules" module.
This adds it back so that if a user invokes 'spack load foo' without
having sourced an environment setup script, they will be prompted
to do so. This also improves the placeholder message to tell the 
user to invoke 'spack' as shell function rather than as an executable.

5 files changed, 30 insertions, 8 deletions

diff --git a/lib/spack/spack/cmd/common/__init__.py b/lib/spack/spack/cmd/common/__init__.py
index 8922701e9f..bb4e45438e 100644
--- a/lib/spack/spack/cmd/common/__init__.py
+++ b/lib/spack/spack/cmd/common/__init__.py
@@ -22,3 +22,25 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
+
+import spack
+from llnl.util import tty
+
+
+def print_module_placeholder_help():
+    """
+    For use by commands to tell user how to activate shell support.
+    """
+    tty.msg("This command requires spack's shell integration.", "",
+            "To initialize spack's shell commands, you must run one of",
+            "the commands below.  Choose the right command for your shell.",
+            "", "For bash and zsh:",
+            "    . %s/setup-env.sh" % spack.share_path, "",
+            "For csh and tcsh:", "    setenv SPACK_ROOT %s" % spack.prefix,
+            "    source %s/setup-env.csh" % spack.share_path, "",
+            "This exposes a 'spack' shell function, which you can use like",
+            "    $ spack load package-foo", "",
+            "Running the Spack executable directly (for example, invoking",
+            "./bin/spack) will bypass the shell function and print this",
+            "placeholder message, even if you have sourced one of the above",
+            "shell integration scripts.")
diff --git a/lib/spack/spack/cmd/load.py b/lib/spack/spack/cmd/load.py
index cb6f8402aa..61c7003855 100644
--- a/lib/spack/spack/cmd/load.py
+++ b/lib/spack/spack/cmd/load.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import argparse
-import spack.modules
+from spack.cmd.common import print_module_placeholder_help
 
 description = "add package to environment using `module load`"
 section = "environment"
@@ -40,4 +40,4 @@ def setup_parser(subparser):
 
 
 def load(parser, args):
-    spack.modules.print_help()
+    print_module_placeholder_help()
diff --git a/lib/spack/spack/cmd/unload.py b/lib/spack/spack/cmd/unload.py
index 3255a4835e..9820ff52d3 100644
--- a/lib/spack/spack/cmd/unload.py
+++ b/lib/spack/spack/cmd/unload.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import argparse
-import spack.modules
+from spack.cmd.common import print_module_placeholder_help
 
 description = "remove package from environment using `module unload`"
 section = "environment"
@@ -39,4 +39,4 @@ def setup_parser(subparser):
 
 
 def unload(parser, args):
-    spack.modules.print_help()
+    print_module_placeholder_help()
diff --git a/lib/spack/spack/cmd/unuse.py b/lib/spack/spack/cmd/unuse.py
index c07b21e0d4..14ca4227d2 100644
--- a/lib/spack/spack/cmd/unuse.py
+++ b/lib/spack/spack/cmd/unuse.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import argparse
-import spack.modules
+from spack.cmd.common import print_module_placeholder_help
 
 description = "remove package from environment using dotkit"
 section = "environment"
@@ -39,4 +39,4 @@ def setup_parser(subparser):
 
 
 def unuse(parser, args):
-    spack.modules.print_help()
+    print_module_placeholder_help()
diff --git a/lib/spack/spack/cmd/use.py b/lib/spack/spack/cmd/use.py
index 11559fc7ff..956f5c6cbc 100644
--- a/lib/spack/spack/cmd/use.py
+++ b/lib/spack/spack/cmd/use.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import argparse
-import spack.modules
+from spack.cmd.common import print_module_placeholder_help
 
 description = "add package to environment using dotkit"
 section = "environment"
@@ -39,4 +39,4 @@ def setup_parser(subparser):
 
 
 def use(parser, args):
-    spack.modules.print_help()
+    print_module_placeholder_help()