My question here is how does perl decide which Config.pm it uses?

I think I solved my own question here. When perl looks for Config.pm it starts at the top of @INC and keeps on going until it finds a match. I conjecture that it's guaranteed that there is one at the ultimate path with perl-base:

$ ./2.cf.pl 
</usr/lib/x86_64-linux-gnu/perl/5.26>
---------------
/home/bob/perl5/lib/perl5/x86_64-linux-gnu-thread-multi /home/bob/perl
+5/lib/perl5 /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.26.1 /us
+r/local/share/perl/5.26.1 /usr/lib/x86_64-linux-gnu/perl5/5.26 /usr/s
+hare/perl5 /usr/lib/x86_64-linux-gnu/perl/5.26 /usr/share/perl/5.26 /
+usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base
path is /usr/lib/x86_64-linux-gnu/perl/5.26/Config.pm
stat is File::stat=ARRAY(0x55f122748b70)
$VAR1 = bless( [
                 2054,
                 6591373,
                 33188,
                 1,
                 0,
                 0,
                 0,
                 3372,
                 1539824438,
                 1531923663,
                 1532749911,
                 4096,
                 8
               ], 'File::stat' );

path is /usr/lib/x86_64-linux-gnu/perl-base/Config.pm
stat is File::stat=ARRAY(0x55f122ad48c0)
$VAR1 = bless( [
                 2054,
                 6591655,
                 33188,
                 1,
                 0,
                 0,
                 0,
                 3373,
                 1539712704,
                 1531923663,
                 1532749916,
                 4096,
                 8
               ], 'File::stat' );

$ cat 2.cf.pl
#!/usr/bin/perl -w
use 5.011;
use utf8;
use Config qw/%Config config_vars/;
use Path::Tiny;
use Data::Dumper;
my $insarchname = $Config{'installarchlib'};
print "<$insarchname>\n";
say "---------------";
say "@INC";

foreach (@INC) {
  my $path1 = path( $_, "Config.pm" );
  if ( -f $path1 ) {
    my $stat = $path1->stat;
    say "path is $path1";
    say "stat is $stat";
    say Dumper $stat;
  }

}
$

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In reply to Re^3: how to get Config values into a hash by Aldebaran
in thread how to get Config values into a hash by Aldebaran

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