5 perldelta - what is new for perl v5.39.1
9 This document describes differences between the 5.39.0 release and the 5.39.1
12 If you are upgrading from an earlier release such as 5.38.0, first read
13 L<perl5390delta>, which describes differences between 5.38.0 and 5.39.0.
15 =head1 Incompatible Changes
17 =head2 reset EXPR now calls set-magic on scalars
19 Previously C<reset EXPR> did not call set magic when clearing scalar variables.
20 This meant that changes did not propagate to the underlying internal state
21 where needed, such as for C<$^W>, and did not result in an exception where the
22 underlying magic would normally throw an exception, such as for C<$1>.
24 This means code that had no effect before may now actually have an effect,
25 including possibly throwing an exception.
27 C<reset EXPR> already called set magic when modifying arrays and hashes.
29 This has no effect on plain C<reset> used to reset one-match searches as with
32 [L<GH #20763|https://github.com/Perl/perl5/issues/20763>]
34 =head2 Calling the import method of an unknown package produces an error
36 Historically, it has been possible to call the import() or unimport() method of
37 any class, including ones which have not been defined, with an argument and not
38 experience an error. For instance, this code will not throw an error in Perl
41 Class::That::Does::Not::Exist->import("foo");
43 However, as of Perl 5.39.1 this will throw an exception. Note that calling
44 these methods with no arguments continues to silently succeed and do nothing.
47 Class::That::Does::Not::Exist->import();
49 will continue to not throw an error. This is because every class implicitly
50 inherits from the class UNIVERSAL which now defines an import method. In older
51 perls there was no such method defined, and instead the method calls for
52 C<import> and C<unimport> were special cased to not throw errors if there was
53 no such method defined.
55 This change has been added because it makes it easier to detect case typos in
56 C<use> statements when running on case-insensitive file systems. For instance,
57 on Windows or other platforms with case-insensitive file systems on older perls
62 would silently do nothing as the module is actually called 'strict.pm', not
63 'STRICT.pm', so it would be loaded but its import method would never be called.
64 It will also detect cases where a user passes an argument when using a package
65 that does not provide its own import, for instance most "pure" class
66 definitions do not define an import method.
68 =head1 Modules and Pragmata
70 =head2 Updated Modules and Pragmata
76 L<Compress::Raw::Bzip2> has been upgraded from version 2.204_001 to 2.205.
80 L<Compress::Raw::Zlib> has been upgraded from version 2.204_001 to 2.205.
84 L<CPAN::Meta::Requirements> has been upgraded from version 2.140 to 2.143.
88 L<Errno> has been upgraded from version 1.37 to 1.38.
90 The C<osvers> and C<archname> baked into the module to ensure Errno is loaded
91 by the perl that built it are now more comprehensively escaped.
92 [L<GH #21135|https://github.com/Perl/perl5/issues/21135>]
96 L<ExtUtils::CBuilder> has been upgraded from version 0.280238 to 0.280239.
100 L<ExtUtils::Manifest> has been upgraded from version 1.73 to 1.75.
104 L<feature> has been upgraded from version 1.82 to 1.83.
108 IO-Compress has been upgraded from version 2.204 to 2.205.
112 L<Math::BigInt> has been upgraded from version 1.999837 to 1.999839.
116 L<Math::BigInt::FastCalc> has been upgraded from version 0.5013 to 0.5014.
120 L<Module::CoreList> has been upgraded from version 5.20230520 to 5.20230720.
124 L<Module::Metadata> has been upgraded from version 1.000037 to 1.000038.
128 L<perlfaq> has been upgraded from version 5.20210520 to 5.20230701.
132 L<POSIX> has been upgraded from version 2.13 to 2.14.
136 L<Socket> has been upgraded from version 2.036 to 2.037.
140 L<Test::Simple> has been upgraded from version 1.302194 to 1.302195.
144 L<Text::Tabs> has been upgraded from version 2021.0814 to 2023.0511.
148 L<Text::Wrap> has been upgraded from version 2021.0814 to 2023.0511.
152 L<threads> has been upgraded from version 2.36 to 2.37.
156 L<Time::HiRes> has been upgraded from version 1.9775 to 1.9776.
160 L<Time::Local> has been upgraded from version 1.30 to 1.35.
164 L<UNIVERSAL> has been upgraded from version 1.15 to 1.16.
168 L<warnings> has been upgraded from version 1.65 to 1.66.
174 =head2 Changes to Existing Documentation
176 We have attempted to update the documentation to reflect the changes listed in
177 this document. If you find any we have missed, open an issue at
178 L<https://github.com/Perl/perl5/issues>.
180 Additionally, the following selected changes have been made:
182 =head3 L<perlhacktips>
188 Document we can't use compound literals or array designators due to C++
189 compatibility. [L<GH #21073|https://github.com/Perl/perl5/issues/21073>]
195 The following additions or changes have been made to diagnostic output,
196 including warnings and fatal error messages. For the complete list of
197 diagnostic messages, see L<perldiag>.
199 =head2 New Diagnostics
207 L<Attempt to call undefined %s method with arguments via package "%s" (perhaps
208 you forgot to load the package?)|perldiag/"Attempt to call undefined %s method
209 with arguments via package "%s" (perhaps you forgot to load the package?)">
211 (F) You called the C<import()> or C<unimport()> method of a class that has no
212 import method defined in its inheritance graph, and passed an argument to the
213 method. This is very often the sign of a misspelled package name in a use or
214 require statement that has silently succeeded due to a case-insensitive file
217 Another common reason this may happen is when mistakenly attempting to import
218 or unimport a symbol from a class definition or package which does not use
219 C<Exporter> or otherwise define its own C<import> or C<unimport> method.
225 Tests were added and changed to reflect the other additions and changes in this
226 release. Furthermore, these significant changes were made:
232 Update F<nm> output parsing for Darwin in F<t/porting/libperl.t> to handle
233 changes in the output of nm on Darwin.
234 [L<GH #21117|https://github.com/Perl/perl5/issues/21117>]
238 =head1 Platform Support
240 =head2 Platform-Specific Notes
246 Eliminated several header build warnings under MSVC with C</W4> to reduce noise
247 for embedders. [L<GH #21031|https://github.com/Perl/perl5/issues/21031>]
251 =head1 Acknowledgements
253 XXX Generate this with:
255 perl Porting/acknowledgements.pl v5.39.0..HEAD
257 =head1 Reporting Bugs
259 If you find what you think is a bug, you might check the perl bug database at
260 L<https://github.com/Perl/perl5/issues>. There may also be information at
261 L<http://www.perl.org/>, the Perl Home Page.
263 If you believe you have an unreported bug, please open an issue at
264 L<https://github.com/Perl/perl5/issues>. Be sure to trim your bug down to a
265 tiny but sufficient test case.
267 If the bug you are reporting has security implications which make it
268 inappropriate to send to a public issue tracker, then see L<perlsec/SECURITY
269 VULNERABILITY CONTACT INFORMATION> for details of how to report the issue.
273 If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you
274 can do so by running the C<perlthanks> program:
278 This will send an email to the Perl 5 Porters list with your show of thanks.
282 The F<Changes> file for an explanation of how to view exhaustive details on
285 The F<INSTALL> file for how to build Perl.
287 The F<README> file for general stuff.
289 The F<Artistic> and F<Copying> files for copyright information.