In /usr/bin/arch-test line 55:
        HELPER_F="$(basename $HELPERS$1)"
                                     ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
        HELPER_F="$(basename $HELPERS"$1")"


In /usr/bin/arch-test line 57:
        trap "rm '$CHROOT/$HELPER_F'" 0
                  ^-----^ SC2064: Use single quotes, otherwise this expands now rather than when signalled.
                          ^-------^ SC2064: Use single quotes, otherwise this expands now rather than when signalled.


In /usr/bin/arch-test line 58:
        MSG=`chroot "$CHROOT" /"$HELPER_F" 2>/dev/null`
            ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
        MSG=$(chroot "$CHROOT" /"$HELPER_F" 2>/dev/null)


In /usr/bin/arch-test line 60:
        MSG=`$HELPERS$1 2>/dev/null`
            ^----------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                     ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
        MSG=$($HELPERS"$1" 2>/dev/null)


In /usr/bin/arch-test line 62:
    if [ $? -eq 0 -a "x$MSG" = "xok" ]
         ^-- SC2181: Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.
                  ^-- SC2166: Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.


In /usr/bin/arch-test line 68:
for x in $HELPERS*
         ^------^ SC2231: Quote expansions in this for loop glob to prevent wordsplitting, e.g. "$dir"/*.txt .


In /usr/bin/arch-test line 72:
    MSG=`"$x" 2>/dev/null|tr -d '\r'`
        ^---------------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
    MSG=$("$x" 2>/dev/null|tr -d '\r')


In /usr/bin/arch-test line 73:
    if [ $? -eq 0 -a "x$MSG" = "xok" ]
         ^-- SC2181: Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.
                  ^-- SC2166: Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.

For more information:
  https://www.shellcheck.net/wiki/SC2064 -- Use single quotes, otherwise this...
  https://www.shellcheck.net/wiki/SC2166 -- Prefer [ p ] && [ q ] as [ p -a q...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...