In /usr/bin/xml2-config line 24:
    exit $1
         ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    exit "$1"


In /usr/bin/xml2-config line 33:
    -*=*) 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/xml2-config line 45:
	echo $prefix
             ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
	echo "$prefix"


In /usr/bin/xml2-config line 54:
      echo $exec_prefix
           ^----------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
      echo "$exec_prefix"


In /usr/bin/xml2-config line 94:
    echo $cflags $libs
         ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    echo "$cflags" $libs

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...