[entropy.const] drop etpConst['triggersdir'] global variable

lib/entropy/const.py

@@ -190,7 +190,6 @@ def const_default_settings(rootdir):
     default_etp_dbfile = "packages.db"
     default_etp_dbclientfile = "equo.db"
     default_etp_client_repodir = "/client"
-    default_etp_triggersdir = "/triggers/"+ETP_ARCH_CONST
     default_etp_smartappsdir = "/smartapps/"+ETP_ARCH_CONST
     default_etp_smartpackagesdir = "/smartpackages/"+ETP_ARCH_CONST
     default_etp_cachesdir = "/caches/"
@@ -223,8 +222,7 @@ def const_default_settings(rootdir):
         # etpConst['smartpackagesdir'] location where
         # smart packages files are places
         'smartpackagesdir': default_etp_dir+default_etp_smartpackagesdir,
-        # etpConst['triggersdir'] location where external triggers are placed
-        'triggersdir': default_etp_dir+default_etp_triggersdir,
+
         # directory where entropy stores its configuration
         'confdir': default_etp_confdir,
         # same as above + /packages

lib/entropy/spm/plugins/interfaces/portage_plugin/__init__.py

@@ -1173,7 +1173,8 @@ class PortagePlugin(SpmPlugin):
                 ebuild_path)
 
         data['trigger'] = const_convert_to_rawstring("")
-        trigger_file = os.path.join(etpConst['triggersdir'], data['category'],
+        triggers_dir = SpmPlugin.external_triggers_dir()
+        trigger_file = os.path.join(triggers_dir, data['category'],
             data['name'], etpConst['triggername'])
         if os.access(trigger_file, os.R_OK) and os.path.isfile(trigger_file):
             with open(trigger_file, "rb") as trig_f:

lib/entropy/spm/plugins/skel.py

@@ -12,7 +12,7 @@
 """
 import os
 
-from entropy.const import etpConst
+from entropy.const import etpConst, etpSys
 from entropy.core import Singleton
 from entropy.misc import LogFile
 from entropy.core.settings.base import SystemSettings
@@ -52,6 +52,16 @@ class SpmPlugin(Singleton):
         """
         raise NotImplementedError()
 
+    @staticmethod
+    def external_triggers_dir():
+        """
+        External Entropy triggers executable directory
+        This path should be used by SPM to read the trigger for
+        packages inside extract_package_metadata()
+        """
+        return os.path.join(
+            etpConst['entropyworkdir'], "triggers", etpSys['arch'])
+
     @staticmethod
     def get_package_groups():
         """