printf -v not supported

# Run script on host and Android target
cat prints.sh
fun() {
printf -v __RET '%x' "0xabcd"
echo $__RET
}
fun

$ ./prints.sh
abcd
$ adb push  prints.sh  /data/local/
$ adb shell chmod 777  /data/local/
$ adb shell /data/local/prints.sh
usage: printf FORMAT [ARGUMENT...]

Format and print ARGUMENT(s) according to FORMAT, using C printf syntax
(% escapes for cdeEfgGiosuxX, \ escapes for abefnrtv0 or \OCTAL or \xHEX).

printf: Unknown option v