In /usr/bin/opentool line 33:
  echo usage: `basename "$0"` [--library-combo=...] tool [arguments...]
              ^-------------^ SC2046: Quote this to prevent word splitting.
              ^-------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                              ^-------------------^ SC2102: Ranges can only match single chars (mentioned due to duplicates).
                                                         ^------------^ SC2102: Ranges can only match single chars (mentioned due to duplicates).

Did you mean: 
  echo usage: $(basename "$0") [--library-combo=...] tool [arguments...]


In /usr/bin/opentool line 34:
  echo `basename "$0"` --help for help
       ^-------------^ SC2046: Quote this to prevent word splitting.
       ^-------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
  echo $(basename "$0") --help for help


In /usr/bin/opentool line 48:
  . "$GNUSTEP_CONFIG_FILE"
    ^--------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/opentool line 57:
          . "$GNUSTEP_USER_CONFIG_FILE"
            ^-------------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/opentool line 61:
          . "$GNUSTEP_HOME/$GNUSTEP_USER_CONFIG_FILE"
            ^-- SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/opentool line 73:
GNUSTEP_SH_EXPORT_ALL_VARIABLES=yes
^-----------------------------^ SC2034: GNUSTEP_SH_EXPORT_ALL_VARIABLES appears unused. Verify use (or export if used externally).


In /usr/bin/opentool line 74:
. $GNUSTEP_MAKEFILES/GNUstep.sh
  ^---------------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/opentool line 88:
        . "$tmp_makefiles/GNUstep-reset.sh"
          ^-- SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/opentool line 89:
        LIBRARY_COMBO=`echo "$1" | sed 's/--library-combo=//'`
                      ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
        LIBRARY_COMBO=$(echo "$1" | sed 's/--library-combo=//')


In /usr/bin/opentool line 90:
        . "$tmp_makefiles/GNUstep.sh"
          ^-------------------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.


In /usr/bin/opentool line 95:
      echo usage: `basename "$0"` [--library-combo=...] tool [arguments...]
                  ^-------------^ SC2046: Quote this to prevent word splitting.
                  ^-------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                                  ^-------------------^ SC2102: Ranges can only match single chars (mentioned due to duplicates).
                                                             ^------------^ SC2102: Ranges can only match single chars (mentioned due to duplicates).

Did you mean: 
      echo usage: $(basename "$0") [--library-combo=...] tool [arguments...]


In /usr/bin/opentool line 100:
      echo [arguments...] are the arguments to the tool.
           ^------------^ SC2102: Ranges can only match single chars (mentioned due to duplicates).


In /usr/bin/opentool line 119:
	tool_dir=`dirname "$tool"`; 
                 ^---------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
	tool_dir=$(dirname "$tool"); 


In /usr/bin/opentool line 120:
	tool_dir=`(cd "$tool_dir"; pwd)`; 
                 ^---------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                   ^------------^ SC2164: Use 'cd ... || exit' or 'cd ... || return' in case cd fails.

Did you mean: 
	tool_dir=$((cd "$tool_dir" || exit; pwd)); 


In /usr/bin/opentool line 121:
	tool_name=`basename "$tool"`;
                  ^----------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
	tool_name=$(basename "$tool");

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/SC2046 -- Quote this to prevent word splitt...