Thanks to Alec for suggesting a way to capture the error message!
Here it is:
+ perl -e 'use DateTime::Format::ISO8601;'
The 'regex' parameter ("(?x-ism:^ (\d{4}) (\d\d) (\d\d) $)") to
DateTime::Format::Builder::Parser::create_single_parser was an
'unknown', which is not one of the allowed types: scalarref
at /usr/lib/perl5/vendor_perl/Params/ValidatePP.pm line 650
Params::Validate::__ANON__('The \'regex\' parameter ("(?x-ism:^
(\d{4}) (\d\d) (\d\d) $)"...') called at
/usr/lib/perl5/vendor_perl/Params/ValidatePP.pm line 494
Params::Validate::_validate_one_param('Regexp=REGEXP(0xa3de900)',
'HASH(0xa3ec050)', 'HASH(0xa3aab08)', 'The \'regex\'
parameter
("(?x-ism:^ (\d{4}) (\d\d) (\d\d) $)")') called at
/usr/lib/perl5/vendor_perl/Params/ValidatePP.pm line 353
Params::Validate::validate('ARRAY(0xa386368)', 'HASH(0xa385c98)')
called at /usr/share/perl5/vendor_perl/DateTime/Format/Builder/Parser.pm
line 311
DateTime::Format::Builder::Parser::create_single_parser(undef,
'params', 'ARRAY(0xa3de890)', 'length', 8, 'regex',
'Regexp=REGEXP(0xa3de900)') called at
/usr/share/perl5/vendor_perl/DateTime/Format/Builder/Parser.pm line
501
DateTime::Format::Builder::Parser::sort_parsers('DateTime::Format::Builder::Parser',
'HASH(0xa38d760)', 'ARRAY(0xa38cd20)') called at
/usr/share/perl5/vendor_perl/DateTime/Format/Builder/Parser.pm line
397
DateTime::Format::Builder::Parser::create_multiple_parsers('DateTime::Format::Builder::Parser',
'HASH(0xa38d760)', 'HASH(0xa3de8e0)', 'HASH(0xa3de9c0)',
'HASH(0xa3dea70)', 'HASH(0xa3deb10)', 'HASH(0xa3debc0)',
'HASH(0xa3dece0)', 'HASH(0xa3dedf0)', ...) called at
/usr/share/perl5/vendor_perl/DateTime/Format/Builder/Parser.pm line
600
DateTime::Format::Builder::Parser::create_parser('DateTime::Format::Builder::Parser',
'ARRAY(0xa2ac098)', 'HASH(0xa3de8e0)', 'HASH(0xa3de9c0)',
'HASH(0xa3dea70)', 'HASH(0xa3deb10)', 'HASH(0xa3debc0)',
'HASH(0xa3dece0)', 'HASH(0xa3dedf0)', ...) called at
/usr/share/perl5/vendor_perl/DateTime/Format/Builder.pm line 156
DateTime::Format::Builder::create_parser('DateTime::Format::Builder',
'ARRAY(0xa3e9f28)') called at
/usr/share/perl5/vendor_perl/DateTime/Format/Builder.pm line 174
DateTime::Format::Builder::create_end_parser('DateTime::Format::Builder',
'ARRAY(0xa3e9f28)') called at
/usr/share/perl5/vendor_perl/DateTime/Format/Builder.pm line 104
DateTime::Format::Builder::create_class(undef, 'parsers',
'HASH(0xa3eb750)') called at
/usr/share/perl5/vendor_perl/DateTime/Format/ISO8601.pm line 175
require DateTime/Format/ISO8601.pm called at -e line 1
main::BEGIN() called at
/usr/share/perl5/vendor_perl/DateTime/Format/ISO8601.pm line 0
eval {...} called at
/usr/share/perl5/vendor_perl/DateTime/Format/ISO8601.pm line 0
Compilation failed in require at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
Thanks,
Richard