[Help-bash] GNU bash, version 4.4 – A valid command is not performed

[Ricky Tigg]

Hi GNU bash team. A valid  command – at least it seems as such – does not
create users. – OS: Fedora.

$ echo $SHELL
/bin/bash
$ bash --version|head -n1
GNU bash, version 4.4.23(1)-release (x86_64-redhat-linux-gnu)

In my user home directory is a file containing a Users/groups list. The
permission 'x' has been added:

$ ls -l users_groups
-rwxr--r--. 1 yk yk 171 11.12. 12:25 users_groups
$ cat users_groups
#!/usr/bin/env bash

declare -A groups=(
    ["test_user"]="wheel,users"
)

$ sudo su
# pwd
/home/yk

The following command purpose is to create users and add them to groups.

# for user in "address@hidden"; do useradd -U -G "${groups[$user]}" "$user";
done < users_groups
#

Above command unexpectedly does not create users and subsequently cannot
associate them to the specified groups.

# groups test_user
groups: 'test_user': no such user

Any advice is welcome. Thanks, R.T.