Bash 4.4-alpha no longer expands ${!prefix@}.
${!prefix*} however still works.
bash-4.4-alpha-4.4# var_1=a var_2=b
bash-4.4-alpha-4.4# set -- ${!var_@}
bash-4.4-alpha-4.4# echo $#
0
bash-4.4-alpha-4.4# set -- "${!var_@}"
bash-4.4-alpha-4.4# echo $#
1
bash-4.4-alpha-4.4# set -- ${!var_*}
bash-4.4-alpha-4.4# echo $#
2
konsolebox
