Perl in Intellij IDEA: Global symbol "%Config" requires explicit package name (did you forget to declare "my %Config"?) lib.pm - perl

Question

I'm developing a large perl module which works like a charm when running from Terminal. When running i with Intellij IDEA CE, the following error pops up. This happens in all major versions of the software.
My programm starts:
#!/usr/bin/env perl
use strict;
use warnings;
use utf8;
use feature qw (say);
use Getopt::Long;
use lib 'lib';
die('this is a test');
...
Perls own lib.pm starts like this
package lib;
# THIS FILE IS AUTOMATICALLY GENERATED FROM lib_pm.PL.
# ANY CHANGES TO THIS FILE WILL BE OVERWRITTEN BY THE NEXT PERL BUILD.
use Config;
use strict;
my $archname = $Config{archname};
my $version = $Config{version};
my #inc_version_list = reverse split / /, $Config{inc_version_list};
our #ORIG_INC = #INC; # take a handy copy of 'original' value
our $VERSION = '0.65';
...
In Intellij IDEA this leads to
/usr/bin/perl -I/home/user/git/mytool/lib -I/home/user/git/mytool/lib/Download /home/user/git/mytool/download.pl Digi20
Global symbol "%Config" requires explicit package name (did you forget to declare "my %Config"?) at /usr/lib/x86_64-linux-gnu/perl-base/lib.pm line 10.
Global symbol "%Config" requires explicit package name (did you forget to declare "my %Config"?) at /usr/lib/x86_64-linux-gnu/perl-base/lib.pm line 11.
Global symbol "%Config" requires explicit package name (did you forget to declare "my %Config"?) at /usr/lib/x86_64-linux-gnu/perl-base/lib.pm line 12.
Compilation failed in require at /home/user/git/mytool/download.pl line 10.
I don't know where these -I params to the perl executable are configured. In the run dialog, i configured no params for perl.
Ubuntu 22.04 LTA + Perl 5.34. On my home office machine everything works fine, too. But on the office machine not. Syncing IDE settings home > office does not help.
Found another user having a similar issue on Eclipse but the error comes from another module. My Config module is already named Download::Config.

Answer 1

There's a module call Config that comes with Perl. It exports a hash named %Config by default.
The error is due to %Config not being exported by by use Config;.
I'm guessing a different module named Config is being picked up by use Config;. You can verify this using BEGIN { print "$INC{'Config.pm'}\n" } after the use Config;.
You should name your module something else.
That said, I suspect you don't actually have a module named Config. I suspect you have a module named Download::Config (which is perfectly fine), but /home/user/git/mytool/lib/Download is being incorrectly added to #INC.

Answer 2

I found the solution:
Intellij IDEA adds the configured library destinations as -I param to the perl call. Mind the purple marker here in the picture. The Download folder was purple, too. That caused the error.
There is a similar setting in the project structure settings but this does not cause -I parameters being added.