Trac #14750: sysconfdir not respected/implemented

Configuration files should be placed into 'sysconfdir' [1]. Files such
as gprc.expect in $(SAGE_LOCAL)/etc or default.qepcadrc in $(SAGE_LOCAL)
will break future sagelib packaging.
SAGE_LOCAL will supposedly be set to 'prefix' for Sage-the-library
packages.

It might make sense to add SAGE_ETC=sysconfdir to the environment (and
use that whereever appropriate). sysconfdir defaults to prefix/etc
(=SAGE_LOCAL/etc) but can be overridden for custom installations.

[1] www.gnu.org/prep/standards/html_node/Directory-Variables.html‎

URL: http://trac.sagemath.org/14750
Reported by: felixs
Ticket author(s): Felix Salfelder
Reviewer(s): Nathann Cohen

src/bin/sage-env

@@ -246,6 +246,7 @@ fi
 
 # Setting Sage-related location environment variables.
 export SAGE_LOCAL="$SAGE_ROOT/local"
+export SAGE_ETC="$SAGE_LOCAL/etc"
 export SAGE_SHARE="$SAGE_LOCAL/share"
 export SAGE_EXTCODE="$SAGE_SHARE/sage/ext"
 export SAGE_SPKG_INST="$SAGE_LOCAL/var/lib/sage/installed"

src/sage/env.py

@@ -87,6 +87,7 @@ def _add_variable_or_fallback(key, fallback, force=False):
 # bunch of sage directories and files
 _add_variable_or_fallback('SAGE_ROOT',       None)
 _add_variable_or_fallback('SAGE_LOCAL',      opj('$SAGE_ROOT', 'local'))
+_add_variable_or_fallback('SAGE_ETC',        opj('$SAGE_LOCAL', 'etc'))
 _add_variable_or_fallback('SAGE_SHARE',      opj('$SAGE_LOCAL', 'share'))
 
 # SAGE_LIB is the site-packages directory if the sage library

src/sage/interfaces/gp.py

@@ -977,11 +977,11 @@ def is_GpElement(x):
     """
     return isinstance(x, GpElement)
 
-from sage.env import DOT_SAGE, SAGE_LOCAL
+from sage.env import DOT_SAGE, SAGE_ETC
 import os
 
-# Set GPRC environment variable to $SAGE_LOCAL/etc/gprc.expect
-os.environ["GPRC"] = os.path.join(SAGE_LOCAL, 'etc', 'gprc.expect')
+# Set GPRC environment variable to $SAGE_ETC/gprc.expect
+os.environ["GPRC"] = os.path.join(SAGE_ETC, 'gprc.expect')
 
 # An instance
 gp = Gp(logfile=os.path.join(DOT_SAGE,'gp-expect.log')) # useful for debugging!