rtgtargmkr.pl fails with: "DBD::mysql::st execute failed: No database selected"

[4001982248998]

Hi, after successfully(?) compiling rtg2 on Debian 9.3 with mariadb 10.1.26, I am stuck at generating targets.cfg, because rtgtargmkr.pl fails like this:

sudo /usr/local/rtg2/etc/rtgtargmkr.pl 
Poking <host:community> (public) (64 bit)...
DBD::mysql::st execute failed: No database selected at /usr/local/rtg2/etc/rtgtargmkr.pl line 129.
can't execute the query: DBI::st=HASH(0x556c29028e30)->errstr

But the database exists:

sudo /usr/local/rtg2/etc/createdb mysqlroot

/usr/local/rtg2/etc/createdb setting up MySQL database for RTG.
Using MySQL binaries in /usr/bin.

Adding user "snmp" to MySQL database...
ERROR 1062 (23000) at line 1: Duplicate entry 'localhost-snmp' for key 'PRIMARY'
Creating RTG database "rtg"...
/usr/bin/mysqladmin: CREATE DATABASE failed; error: 'Can't create database 'rtg'; database exists'
Reloading MySQL privileges...
Creating RTG tables...
ERROR 1050 (42S01) at line 5: Table 'router' already exists
Done.

What could I do?

[4001982248998]

maybe a subsequent error from a wrong configuration path in rtgtargmkr.pl