CPAN::Reporter: error loading Test::Reporter::Transport::Metabase.

On FreeBSD-12 I have CPAN::Reporter and Task::CPAN::Reporter installed. 
In ~/.cpan/CPAN/MyConfig.pm I have set:  'test_report' => q[1],

But when I use the 'cpan' shell to 'install' or 'test' CPAN distros, no 
test report is generated or sent.  Here is typical output:

#####
cpan[2]> test ExtUtils::ModuleMaker
Running test for module 'ExtUtils::ModuleMaker'
Checksum for 
/home/jkeenan/.cpan/sources/authors/id/J/JK/JKEENAN/ExtUtils-ModuleMaker-0.63.tar.gz 
ok
Configuring J/JK/JKEENAN/ExtUtils-ModuleMaker-0.63.tar.gz with Makefile.PL

CPAN::Reporter: error loading Test::Reporter::Transport::Metabase. 
Please install the missing module or choose a different transport mechanism.

Checking if your kit is complete...
Looks good
Generating a Unix-style Makefile
Writing Makefile for ExtUtils::ModuleMaker
Writing MYMETA.yml and MYMETA.json
(/usr/local/bin/perl Makefile.PL exited with 0)
CPAN::Reporter: Makefile.PL result is 'pass', No errors.
   JKEENAN/ExtUtils-ModuleMaker-0.63.tar.gz
   /usr/local/bin/perl Makefile.PL -- OK
Running make for J/JK/JKEENAN/ExtUtils-ModuleMaker-0.63.tar.gz

CPAN::Reporter: error loading Test::Reporter::Transport::Metabase. 
Please install the missing module or choose a different transport mechanism.

...

All tests successful.
Files=18, Tests=1589,  4 wallclock secs ( 0.13 usr  0.05 sys +  3.32 
cusr  0.59 csys =  4.09 CPU)
Result: PASS
(/usr/bin/make test exited with 0)
CPAN::Reporter: Test result is 'pass', All tests successful.
CPAN::Reporter: preparing a CPAN Testers report for 
ExtUtils-ModuleMaker-0.63

CPAN::Reporter: error loading Test::Reporter::Transport::Metabase. 
Please install the missing module or choose a different transport mechanism.

CPAN::Reporter: problem with Test::Reporter transport:
Test::Reporter: could not load 'Test::Reporter::Transport::Metabase'
Attempt to reload Test/Reporter/Transport/Metabase.pm aborted.
Compilation failed in require at (eval 192) line 1.

  at /usr/local/lib/perl5/site_perl/CPAN/Reporter.pm line 464.

Test report will not be sent
   JKEENAN/ExtUtils-ModuleMaker-0.63.tar.gz
   /usr/bin/make test -- OK
#####

This is similar to a problem about which I posted to this list in April 
2020.  Thread started here:
https://www.nntp.perl.org/group/perl.cpan.testers.discuss/2020/04/msg4477.html

Why am I getting this spurious "missing module" failure?  What can I do 
to fix it?

Thank you very much.
Jim Keenan