Env mod 4

lib/spack/spack/environment.py

@@ -361,8 +361,52 @@ def from_sourcing_file(filename, *args, **kwargs):
             env_after = dict((k.encode('utf-8'), v.encode('utf-8'))
                              for k, v in env_after.items())
 
-        # Other variables unrelated to sourcing a file
-        blacklist.extend(['SHLVL', '_', 'PWD', 'OLDPWD', 'PS2'])
+        # TODO: Factor out remaining part of this function into something like:
+        #   EnvironmentModifications.diff(from_dict, to_dict,
+        #       clean=..., blacklist=..., whitelist=...)
+        # (Should be a natural fit, given the class name.)
+
+        # Variables unrelated to sourcing a file.
+        # ---------------------------------------------------------------------
+        # *This* blacklist is applied on INPUT (sourcing a shell file). It is
+        # distinct from "environment_blacklist" in modules.yaml, which is
+        # applied on OUTPUT to a specific module flavor.
+        # ---------------------------------------------------------------------
+        blacklist.extend(
+            ' SHLVL _ PWD OLDPWD PS2 ENV'                   # Bash internals
+            ' LOADEDMODULES _LMFILES_ BASH_FUNC_module()'   # env-mod-4
+            ''.split())
+        # ---------------------------------------------------------------------
+        # Given the way we interpret a file here, namely, by having a child
+        # shell source it, there may be interference from any sort of
+        # re-initialization that is done in that shell's dotfiles.  Environment
+        # variables may differ in the child shell from those in the parent
+        # shell that Spack was called from.
+        #
+        # Variables related to a user's chosen Modules implementation are of
+        # particular concern, since the results of the present function usually
+        # end up in a modulefile. This can be terribly confusing.  Notably, in
+        # Environment-Modules-4.x, the definition of the "module" shell
+        # function, and thus the content of "BASH_FUNC_module()", varies
+        # between interactive and non-interactive shell sessions. See function
+        # renderAutoinit in
+        #   https://github.com/cea-hpc/modules/blob/master/modulecmd.tcl.in
+        # (Tcl code), as of 2018-04:
+        #
+        #   # only redirect module from stderr to stdout when session is
+        #   # attached to a terminal to avoid breaking non-terminal session
+        #   # (scp, sftp, etc)
+        #   if {[isStderrTty]} {
+        #      set fname "_moduleraw"
+        #   } else {
+        #      set fname "module"
+        #   }
+        #
+        #
+        # NB2: "filename" could conceivably use some sort of "module" commands
+        # internally, but this should have little direct impact here; should
+        # specific blacklisting be needed, leave that to the caller.
+        # ---------------------------------------------------------------------
 
         def set_intersection(fullset, *args):
             # A set intersection using string literals and regexs
@@ -458,6 +502,7 @@ def return_separator_if_any(*args):
                     search = sep.join(after_list[start:end + 1])
                 except IndexError:
                     env.prepend_path(x, after)
+                    continue        # all set; plus: avoid UnboundLocalError
 
                 if search not in before:
                     # We just need to set the variable to the new value
@@ -534,8 +579,8 @@ def validate(env, errstream):
 
 
 def filter_environment_blacklist(env, variables):
-    """Generator that filters out any change to environment variables present in
-    the input list.
+    """Generator that filters out any change to environment variables present
+    in the input list.
 
     Args:
         env: list of environment modifications

lib/spack/spack/modules/common.py

@@ -580,7 +580,13 @@ def environment_modifications(self):
                 pass
             x.name = str(x.name).replace('-', '_')
 
-        return [(type(x).__name__, x) for x in env if x.name not in blacklist]
+        # blacklist WILL be None if the keyword is present in the YAML configs
+        # but without any entries or with all entries commented out.
+        if blacklist is None:
+            tty.debug('blacklist is defined but empty in your configuration.')
+
+        return [(type(x).__name__, x) for x in env if (
+            blacklist is None or x.name not in blacklist)]
 
     @tengine.context_property
     def autoload(self):