In /usr/bin/gnustep-config line 143:
  . "$GNUSTEP_CONFIG_FILE"
    ^--------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/gnustep-config line 155:
          . "$GNUSTEP_USER_CONFIG_FILE"
            ^-------------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/gnustep-config line 159:
          . "$GNUSTEP_HOME/$GNUSTEP_USER_CONFIG_FILE"
            ^-- SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/gnustep-config line 205:
  --installation-domain-for=*) gs_package_name=`echo "$1" | sed -e 's/--installation-domain-for=//'`
                                               ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
  --installation-domain-for=*) gs_package_name=$(echo "$1" | sed -e 's/--installation-domain-for=//')


In /usr/bin/gnustep-config line 209:
                gs_target=`echo "$1" | sed -e 's/--target-dir-for=//'`
                          ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
                gs_target=$(echo "$1" | sed -e 's/--target-dir-for=//')


In /usr/bin/gnustep-config line 213:
                gs_target=`echo "$1" | sed -e 's/--target-ldir-for=//'`
                          ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
                gs_target=$(echo "$1" | sed -e 's/--target-ldir-for=//')


In /usr/bin/gnustep-config line 221:
GNUSTEP_SH_EXPORT_ALL_VARIABLES=yes
^-----------------------------^ SC2034: GNUSTEP_SH_EXPORT_ALL_VARIABLES appears unused. Verify use (or export if used externally).


In /usr/bin/gnustep-config line 222:
. $GNUSTEP_MAKEFILES/GNUstep.sh
  ^---------------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/gnustep-config line 228:
gs_variable_name=`echo "$1" | sed -e 's/--variable=//'`
                 ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
gs_variable_name=$(echo "$1" | sed -e 's/--variable=//')


In /usr/bin/gnustep-config line 229:
gs_variable_value=`eval echo '$'"$gs_variable_name"`
                  ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
gs_variable_value=$(eval echo '$'"$gs_variable_name")

For more information:
  https://www.shellcheck.net/wiki/SC1090 -- Can't follow non-constant source....
  https://www.shellcheck.net/wiki/SC2034 -- GNUSTEP_SH_EXPORT_ALL_VARIABLES a...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...