In /usr/bin/apu-1-config line 99:
    -*=*) optarg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
                 ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
    -*=*) optarg=$(echo "$1" | sed 's/[-_a-zA-Z0-9]*=//') ;;


In /usr/bin/apu-1-config line 109:
    echo $prefix
         ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    echo "$prefix"


In /usr/bin/apu-1-config line 140:
    echo $flags
         ^----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    echo "$flags"

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...