pretest report: basic install works but tlmgr fails to start: cant find perl script?

[drew]

Hi,

Thanks for the pretest 2020 files!

I'm just using a very basic Plain TeX install, which seems to work on a 
simple dvi production. But I needed to add another couple of packages. 
However the tlmgr doesn't start (gives an error about unable to find 
perl scripts using @INC, but the mentioned file is fact are in the 
installed files)

The first one was TLConfig.pm

After some searching online about perl I found how to place the 
grandparent folder into PERL5LIB. This removed that error but it now 
wants to find :

Can't locate tlmgrgui.pl in @INC (@INC contains: 
/media/DATA/texlive/2020/texmf-dist/scripts/texlive/../../texmf-dist/scripts/texlive 
/media/DATA/texlive/2020/texmf-dist/scripts/texlive/../../tlpkg 
/media/DATA/texlive/2020/tlpkg /usr/lib/perl5/5.30/site_perl 
/usr/share/perl5/site_perl /usr/lib/perl5/5.30/vendor_perl 
/usr/share/perl5/vendor_perl /usr/lib/perl5/5.30/core_perl 
/usr/share/perl5/core_perl) at 
/media/DATA/texlive/2020/texmf-dist/scripts/texlive/tlmgr.pl line 5199.

but as far as I can see this script is in fact in ...../scripts/texlive.

As you can guess, I know nothing about perl.

Drew Krix