In /usr/bin/sfddiff line 1:
#!/usr/bin/fontforge -lang=ff
^-- SC1008: This shebang was unrecognized. ShellCheck only supports sh/bash/dash/ksh. Add a 'shell' directive to specify.


In /usr/bin/sfddiff line 3:
if ( Strtol($version)<20060330 )
   ^-- SC1009: The mentioned syntax error was in this explicit subshell.
     ^-- SC1073: Couldn't parse this function. Fix to allow more checks.
            ^-- SC1065: Trying to declare parameters? Don't. Use () and refer to params as $1, $2..
                     ^-- SC1064: Expected a { to open the function definition.
                     ^-- SC1072:  Fix any mentioned problems and try again.

For more information:
  https://www.shellcheck.net/wiki/SC1008 -- This shebang was unrecognized. Sh...
  https://www.shellcheck.net/wiki/SC1064 -- Expected a { to open the function...
  https://www.shellcheck.net/wiki/SC1065 -- Trying to declare parameters? Don...