[GRASS-dev] [GRASS GIS] #3252: Provide an error message pointing out that session is not active

[GRASS GIS]

#3252: Provide an error message pointing out that session is not active
-------------------------------------------------+-------------------------
 Reporter:  wenzeslaus                           |      Owner:  grass-dev@…
     Type:  defect                               |     Status:  new
 Priority:  normal                               |  Milestone:  7.2.1
Component:  Startup                              |    Version:  unspecified
 Keywords:  GRASS GIS environment variables,     |        CPU:  Unspecified
  g.gisenv, G_getenv, G_getenv_nofatal,          |
  G_fatal_error, fatal error, LOCATION_NAME,     |
  session                                        |
 Platform:  Unspecified                          |
-------------------------------------------------+-------------------------
 When you run

 {{{
 grass73 ~/grassdata/nc_spm_08_grass7/user1 --exec d.mon wx0
 }}}

 it gives

 {{{
 ERROR: Variable 'LOCATION_NAME' not set
 }}}

 it also prints

 {{{
 Traceback (most recent call last):
   File "/home/vpetras/dev/grass/gcc_trunk/dist.x86_64-pc-linux-
 gnu/gui/wxpython/mapdisp/main.py", line 608, in <module>
     fd = open(pidFile, 'w')
 IOError: [Errno 2] No such file or directory:
 '/home/vpetras/grassdata/nc_spm_08_grass7/user1/.tmp/lemur/MONITORS/wx0/pid'
 }}}

 but what it is trying to say is that there is not running in an active
 GRASS GIS session (session ended but d.mon wx0 runs in the background).

 Similar situation can be created in Python using:

 {{{
 #!python
 import os
 import sys
 import subprocess

 # create GRASS GIS runtime environment
 gisbase = subprocess.check_output(["grass", "--config", "path"]).strip()
 os.environ['GISBASE'] = gisbase
 sys.path.append(os.path.join(gisbase, "etc", "python"))

 # do GRASS GIS imports
 import grass.script as gs
 import grass.script.setup as gsetup

 # set GRASS GIS session data
 rcfile = gsetup.init(gisbase, "/home/vpetras/grassdata",
 "nc_spm_08_grass7", "user1")

 # run module
 gs.parse_command('g.region', region="swwake_30m", flags='pg')

 # end the GRASS session
 os.remove(rcfile)

 # run module again
 gs.parse_command('g.region', region="swwake_30m", flags='pg')
 }}}

 The error is again (possibly with traceback):

 {{{
 ERROR: Variable 'LOCATION_NAME' not set
 }}}

 But it should be one of those (or any other you think is better):

 {{{
 ERROR: No GRASS GIS session is not active: Variable 'LOCATION_NAME' not
 set

 ERROR: Variable 'LOCATION_NAME' not set. Are you in GRASS GIS session?

 ERROR: Variable 'LOCATION_NAME' not set. Are you running GRASS GIS
 session?

 ERROR: Not running in a GRASS GIS session (variable 'LOCATION_NAME' not
 set)
 }}}

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3252>
GRASS GIS <https://grass.osgeo.org>