use CPAN::Meta::Converter;
-delete $ENV{$_} for qw/PERL_JSON_BACKEND PERL_YAML_BACKEND/; # use defaults
+delete $ENV{PERL_YAML_BACKEND};
+delete $ENV{PERL_JSON_BACKEND};
+delete $ENV{CPAN_META_JSON_BACKEND};
+delete $ENV{CPAN_META_JSON_DECODER};
my $spec2 = {
version => '2',