the bug remains open because no one realizes that it has been fixed.
Ideally, every open bug should have a TODO test in the core test suite.
+=head2 deparse warnings nicely
+
+Currently Deparse punts on deparsing the bitmask for warnings, which it
+dumps uglily as-is. Try running this:
+
+ $ ./perl -Ilib -MO=Deparse -e 'use warnings "pipe"; die'
+
+Deparse.pm could use the package variables in warnings.pm that warnings.pm
+itself uses to convert the list passed to it into a bitfield. Deparse just
+needs to reverse that.
+
+=head2 test and fix Deparse with perl's test suite
+
+If you run perl's tests with the TEST_ARGS environment variable set to
+C<-deparse> (e.g., run C<TEST=-deparse make test>), each test file will be
+deparsed and the deparsed output will be run. Currently there are many
+failures, which ought to be fixed. There is in F<Porting/deparse-skips.txt>
+a list of tests known to fail, but it is out of date. Updating it would
+also help.
+
+This is an incremental task. Every small bit helps. It is also a task that
+may never end. As new tests are added, they tickle corner cases that
+B::Deparse cannot yet handle correctly.
+
+This task I<may> need a bit of perl guts knowledge. But what changes need
+to be made is usually easy to see by dumping op trees with B::Concise:
+
+ $ ./perl -Ilib -MO=Concise -e 'foo(); print @_; die $$_'
+
+and adjusting B::Deparse to handle whatever you see B::Concise produce.
+This is also a good way to I<learn> how perl's op trees work.
+
=head1 Tasks that need a little sysadmin-type knowledge
Or if you prefer, tasks that you would learn from, and broaden your skills
On these systems, it might be the default compilation mode, and there
is currently no guarantee that passing no use64bitall option to the
Configure process will build a 32bit perl. Implementing -Duse32bit*
-options would be nice for perl 5.25.2.
+options would be nice for perl 5.26.0.
=head2 Profile Perl - am I hot or not?
These tasks would need C knowledge, and knowledge of how the interpreter works,
or a willingness to learn.
+=head2 fix refaliasing with nested and recursive subroutines
+
+Currently aliasing lexical variables via reference only applies to the
+current subroutine, and does not propagate to inner closures, nor does
+aliasing of outer variables within closures propagate to the outer
+subroutine. This is because each subroutine has its own lexical pad and the
+aliasing works by changing which SV the pad points to.
+
+One possible way to fix this would be to create new ops for accessing
+variables that are closed over. So C<my $x; sub {$x}> would use a new op
+type, say C<padoutsv>, instead of the C<padsv> currently used in the
+sub. That new op would possibly check a flag or some such and see if it
+needs to fetch the variable from an outer pad. If we follow this approach,
+it should be possible at compile time to detect cases where the more
+complex C<padoutsv> op is unnecessary and revert back to the simpler,
+faster C<padsv>. There would need to be corresponding ops for arrays,
+hashes, and subs, too.
+
+There is also a related issue with recursion and C<state> variables. A
+subroutine actually has a list of lexical pads, each one used at a
+different recursion level. If a C<state> variable is aliased to another
+variable after a recursive call to the same subroutine, that higher call
+depth will not see the effect of aliasing, because the second pad will have
+been created already. Similarly, aliasing a state variable within a
+recursive call will not affect outer calls, even though all call depths are
+supposed to share the same C<state> variables.
+
+Both of these bugs affect C<foreach> aliasing, too.
+
=head2 forbid labels with keyword names
Currently C<goto keyword> "computes" the label value:
=head2 repack the optree
+B<Note:> This entry was written in reference to the I<old> slab allocator,
+removed in commit 7aef8e5bd14.
+
Repacking the optree after execution order is determined could allow
removal of NULL ops, and optimal ordering of OPs with respect to cache-line
filling. I think that
=head1 Big projects
Tasks that will get your name mentioned in the description of the "Highlights
-of 5.25.2"
+of 5.26.0"
=head2 make ithreads more robust