missing key "SAGE_LOCAL" while "import sage.all"

edit

Hello I tried to do some debugging in PyDev. I haven't done any math there yet, just tried to import sage.all and failed.

Variable sage.env.SAGE_LOCAL is "/usr/lib/sagemath//local", so maybe OK, maybe not. I don't know where this double slash comes from.When I write $SAGE_LOCAL in bash, I get "/usr/lib/sagemath/local"

This is my sage.env.SAGE_ENV:

 {'SAGE_LOCAL': '/usr/lib/sagemath//local', 'SAGE_IMPORTALL': 'yes', 'SITE_PACKAGES': ['/usr/lib/sagemath/local/lib/python2.7/site-packages', '/usr/lib/sagemath/local/lib/site-python'], 'SAGE_BANNER': '', 'TRAC_SERVER_URI': 'https://trac.sagemath.org', 'SAGE_EXTCODE': '/usr/lib/sagemath//local/share/sage/ext', 'SAGE_CYTHONIZED': '/usr/lib/sagemath//src/build/cythonized', 'SAGE_DOC_SRC': '/usr/lib/sagemath//src/doc', 'SAGE_ETC': '/usr/lib/sagemath//local/etc', 'SAGE_REPO_AUTHENTICATED': 'ssh://git@trac.sagemath.org:2222/sage.git', 'SAGE_STARTUP_FILE': '/home/a/.sage/init.sage', 'SAGE_DOT_GIT': '/usr/lib/sagemath//.git', 'UNAME': 'Linux', 'SAGE_SHARE': '/usr/lib/sagemath//local/share', 'PYTHON_EGG_CACHE': '/home/a/.sage/.python-eggs', 'SAGE_SPKG_INST': '/usr/lib/sagemath//local/var/lib/sage/installed', 'SAGE_REPO_ANONYMOUS': 'git://trac.sagemath.org/sage.git', 'SAGE_DOC': '/usr/lib/sagemath//local/share/doc/sage', 'SAGE_VERSION': '7.3', 'REALM': 'sage.math.washington.edu', 'SAGE_INC': '/usr/lib/sagemath//local/include', 'SAGE_DATE': '2016-08-04', 'SAGE_SRC': '/usr/lib/sagemath//src', 'SAGE_LIB': '/usr/lib/sagemath/local/lib/python2.7/site-packages', 'SAGE_DISTFILES': '/usr/lib/sagemath//upstream', 'LOCAL_IDENTIFIER': 'a-GA-970A-DS3.7845', 'SAGE_ROOT': '/usr/lib/sagemath/', 'HOSTNAME': 'a-GA-970A-DS3', 'SAGE_URL': 'http://sage.math.washington.edu/sage/', 'DOT_SAGE': '/home/a/.sage', 'SAGE_LOGS': '/usr/lib/sagemath//logs/pkgs'}

However SAGE looks for this variable in some dictionary that looks like this (my system variables):

{'PYTHONIOENCODING': 'UTF-8', 'LIBOVERLAY_SCROLLBAR': '0', 'XDG_RUNTIME_DIR': '/run/user/1000', 'XDG_CURRENT_DESKTOP': 'KDE', 'XDG_SESSION_TYPE': 'x11', 'QT_IM_MODULE': 'compose', 'LOGNAME': 'a', 'USER': 'a', 'HOME': '/home/a', 'XDG_VTNR': '7', 'PATH': '/usr/local/bin:/usr/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/lib64/MRO-3.2.3/R-3.2.3/lib/R:/home/a/anaconda2/bin', 'PYTHONUNBUFFERED': '1', 'PAM_KWALLET_LOGIN': '/tmp/kwallet_a.socket', 'KDE_SESSION_VERSION': '5', 'KDE_FULL_SESSION': 'true', 'XDG_SESSION_DESKTOP': 'KDE''...}

Last instruction is

from . import matrix_mpolynomial_dense   in  matrix_space.py

Before:

 else:
            from sage.matrix.matrix_space import is_MatrixSpace

( in definition of class class PolynomialRing_general(sage.algebras.algebra.Algebra in polynomial_ring.py)

And it all started with

   from sage.rings.all      import *

in all.py

Full traceback looks like this (don't think it's useful):

Traceback (most recent call last):
  File "/mnt/dca8bb8a-0bad-49dc-bd48-7f32e4fb2114/Downloads/work/trial/py.py", line 7, in <module>
    import sage.all
  File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/all.py", line 103, in <module>
    from sage.rings.all      import *
  File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/rings/all.py", line 54, in <module>
    from .number_field.all import *
  File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/rings/number_field/all.py", line 9, in <module>
    from .totallyreal import enumerate_totallyreal_fields_prim
  File "sage/rings/number_field/totallyreal_data.pxd", line 12, in init sage.rings.number_field.totallyreal (/usr/lib/sagemath//src/build/cythonized/sage/rings/number_field/totallyreal.c:11599)
  File "sage/rings/number_field/totallyreal_data.pyx", line 39, in init sage.rings.number_field.totallyreal_data (/usr/lib/sagemath//src ...