Module::Build achieves core status, VMS improvements,
and the usual bunch of bug fixes and enhancements.
(Editor's note: after a few silent weeks on use.perl,
the earlier summaries are now available from the
dev.perl.org archive.)
blead in Win32 Yves Orton first starting looking at smoke failures on Win32, and wondered
why he was seeing redefined subroutines in Getopt::Long, but Nicholas
Clark stepped up and said that Yves had been caught out by a glitch that
had since been fixed in the source code.
Steve Hay and Nicholas worked through the failure, which was a
problem of taintedness when . (dot) appears in the PATH
environment variable. A fine example of how hard it is to get
cross-platform platform-dependent code correct.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00939.html
Term::ReadLine, CON: and Term::ReadKey on Win32 (cpan #17773) Johnathon Stowe mentioned the issues he had uncovered with CPAN bug
reports filed against Term::ReadKey. He had traced the problem
to Term::ReadLine using the special device CON: (as in
console) on Win32. One may open such a file directly, and things
will work correctly, but open the file and pass it as a handle to
Term::ReadLine and things start to fall apart, which is in fact
what happens at the moment. Johnathon thought that the best approach
would be to fix Term::ReadLine.
Somebody else's bug http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg01018.html
John L. Allen was failing miserably at getting Oracle and 64-bit perl on AIX to talk to each other, and asked for help. H.Merijn Brand thought that the combination was "like voluntarily having someone tie you down on a bed of nails, and then being whipped with a bunch of rusty barbed wire." Dave Mitchell considered it highly doubtful that one would be able to connect a 32-bit Oracle library to a 64-bit perl.
After trying out different long integer and long double Perl compilations, John succeeded in building a perl with 32-bit integers, long doubles (128 bits) and Oracle all playing nicely.
Alan Olsen, speaking from experience, recommended that John go either full 32-bit, or full 64-bit. Choosing the middle ground just leads to pain and unhappiness.
It can be done http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00008.html
pow failures on AIX with uselongdouble After having done battle with Oracle on AIX, John L. Allen turned his
attention to failures in the test suite, and noticed some misbehaviour
with the pow function. Dominic Dunlop confirmed that something
strange was indeed occurring.
After a bit of detective work, John realised that the problem was
not with perl, but AIX's underlying math libraries. He wrote a small
C program to demonstrate the error, which should allow someone with
the necessary Configure-fu to write the probe to work around the
breakage.
The library and the damage done http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00105.html
@ISA cache invalidation Caching in which package a method is found ensures decent run-time
performance. That is, if an object calls a method unknown to the
current package, it consults @ISA to look for other packages
that may have a suitable method. Once it succeeds in finding it the
first time, it caches the information so that subsequent method
calls can avoid paying the cost of the search. That works fine until
@ISA is modified, in which case the cache has to be invalidated,
which in turn means that objects need to take a fresh look through
the @ISA chain to locate their methods again.
Usually you don't have to care about this at all, it just works. But
some modules extremely tricky things, and can get thrown by changes
to @ISA, and worse, up until now there was no easy way of
determining when it happens.
So Joshua ben Jore wrote B::sub_generation, which provides a handy
technique for letting user code know when cache invalidation occurs.
When asked to explain what this all meant, Joshua provided a short
snippet of code, showing how things can get derailed if code
doesn't realise that @ISA changed. Rafael thought that Joshua's
exposé should be saved somewhere in perlguts.
Talkin' about my B::sub_generation http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00021.html
Module::Build passthrough Makefile.PL Ken Williams made a change to Module::Build::Compat to deal with the
fact that the method call CPAN::Shell->install() doesn't appear to
return anything useful.
Yitzchak Scott-Thoennes wanted to know how one could reliably test to
see whether the install did in fact succeed. Andreas Koenig recommended
using the $module->uptodate method as a suitable work-around.
Ken planned to use that approach soon.
Look for a new version of Module::Build soon http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00031.html
XS SVs Tracking down leaking scalars in XS code is hard.
Andy Armstrong has started to work on Devel::LeakTrace, which
uses a custom run loop, and was
having trouble determining the relationship between where SVs
are created, and where perl reports that they were created.
Dave Mitchell pointed out that since 5.8.1 it has been possible
to compile a perl executable with -DDEBUG_LEAKING_SCALARS,
which adds extra information to SVs, which in turn can be
picked up by something like Devel::Peek. On the other hand,
Andy's approach has the benefit of not requiring a specially
prepared perl.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00066.html http://search.cpan.org/dist/Devel-LeakTrace/
ext and testing Adam Kennedy is working on the Vanilla Perl 5.8.8 distribution, and was
having trouble with some of the tests in the IO:: packages. He didn't
understand how the tests could succeed at all, and wondered how long they
had been failing.
Steve Hay had a look, and saw that the behaviour is dependent on whether
the fork emulation code is used or not. And that some of the tests to
see whether fork is defined or not are quite bizarre.
Nick Ing-Simmons came to the rescue, giving an explanation for why some of the things are the way they are. All in all, it's an area that Needs Work.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00078.html
File::Find Iterative The venerable File::Find module uses a callback scheme, something
beginners to Perl may find a bit unusual. Shlomi Fish looked at
extending it to provide an iterative interface similar to Shlomi's
own File::FTS module.
Randal Schwartz pointed to an article he had written that dealt with
the same issue. Steve Peters noted that the main criterion for
judging patches to File::Find is that they should incur no
speed penalty, thus, for a patch to be accepted, it would need
solid benchmarking.
Nick Ing-Simmons explained that the question of speed was one of system calls. Make one unnecessary call, and the difference would show up for people scanning deep and wide directory trees.
In the end, Shlomi decided to concentrate on File::Find::Object,
as it appeared to be closer to suiting his needs. David Nicol
wondered whether File::Find was thread-safe, and Tels made a
plug for his own File::Walker
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00047.html
File::FTS http://search.cpan.org/dist/File-FTS/
File::Walker http://search.cpan.org/dist/File-Walker/
Devel::DProf? Jarkko Hietaniemi made a plea for someone with too much spare time on
their hands to please take a look at Devel::DProf and fix some its
worst bugs. Andy Lester wanted some test cases.
Jarkko countered with:
$ perl -d:DProf -e 'sub foo { next } for (1) { foo }'
$ perl -d:DProf -e 'use autouse qw(Pod::Usage pod2usage); pod2usage'
Tels searched the RT queue:
http://rt.perl.org/rt3/Ticket/Display.html?id=24058
The bug stops here http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00152.html
Module::Build 0.27_08 added to the standard distribution A first attempt was made to add Module::Build to the core. This was
perhaps the largest thread of the week. It appears the graft has
succeeded, but more work is required.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00167.html
*a=$a=*b;${"a"}=*a; Nicholas returned to the *a=$a=*b;${"a"}=*a;-perl-go-boom bug
and couldn't see a easy way out, short of cheating and getting
the optimiser to spot the sequence and thereby emit a different
op-tree to make the problem go away.
David Nicol wondered whether it was a case of worrying too much about a construct that doesn't come up in practice. chromatic thought that a tool simply should not crash on invalid input.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00169.html
Peter Prymmer sent in a patch for some VMS-specific issues, which Craig Berry applied partially. Peter was lacking a bit of context to understand the reason why Craig did not apply the rest of it, and John E. Malmberg summarised the issue nicely for the vmsperl readership who don't follow p5p, and thus also saved the p5p summariser from having to do so:
Peter's patch http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00170.html
John's summary http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00186.html
Dan "Mr. Encode" Kogai related something he'd heard about non-existent
Unicode properties (like \p{IsBogus}) in pattern matches. Sometimes
perl spits out an error... but not always. Yitzchak was quick to that
the results depended on whether the match had failed or not before the
scanner reached the location of \p property in the target string.
Hugo van der Sanden wasn't even sure one could call it a bug (which
Dan did not say either), but thought that perhaps the utf8 module
could offer something to check for this situation, since, as
Sadahiro-san pointed out, it could be hard to check for user-defined
properties sufficiently early in the general case.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00189.html
Removed a redundant o->op_type http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg01001.html http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00000.html
Non-null optimizations for SvREFCNT_inc http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00032.html
Initialising all of mgvtbl http://www.xray.mpe.mpg.de/maIling-lists/perl5-porters/2006-03/msg00033.html
PERL_TRACK_MEMPOOL cripples environment after exit() Marcus Holland-Moritz uses blead for his daily work, which leads
to some interesting discoveries. He had wanted to run gcov
coverage analysis of one of his XS modules, and became distracted
by strange failures, probably best attributed to the
environment variable code clean out that took place a few months
ago. Evidently there are still demons lurking in that code. Marcus
supplied a patch to nail one of them, applied by Rafael Garcia-Suarez.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00940.html
B::Lint for grep Joshua ben Jore offered a patch to silent what he
perceived to be a useless warning emitted by B::Lint,
concerning implicit matches with grep. Since grep{ /pattern/ }
is such a frequent idiom (and insofar as $_ is topicalised
(the New way of referring to what used to be known as localised)
within the grep code block), it's a rather stupid warning.
Rafael agreed with Joshua and applied the patch, saying that
he'd be happy to accept similar patches for postfix for
and map.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00002.html
John E. Malmberg sent in a patch for VMS builds and long pathname handling. Abe Timmerman reported that results looked good.
The patch http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00122.html
The smoke results http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00127.html
Smoke [5.9.4] 27358 FAIL(F) hp-ux 11.11/64 (PA-2.0/64/2 cpu)
H.Merijn Brand poked around in test.pl to try and cope with change #27345
and problems with tainting. He made the appropriate changes to get things
to work on HP-UX but wondered whether the patch would work on other
systems like VMS or Win32. Steve Hay found problems with the latter,
and proposed an alternative.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00041.html
?{} assertions (#38639) Richard Clayton identified a problem with lexicals defined within a for
and being set within a ?{} assertion of a pattern match. It gets set the
first time through the loop, but not on subsequent iterations. The work-around
is to declare the lexical in a scope further out from the for block.
No takers.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00941.html
Configure -des stops waiting for <CR> (#38642) Anton Koinov ran into problems configuring perl on Gentoo. Andy Dougherty was intrigued, and tried to guess what was going wrong, and suggested Anton run the following command
sh -x ./Configure -S 2>&1 | tee Configure.out
... in order to capture all of the text generated during the run (as
-des discards certain output deemed to be mostly harmless). No news
back from Anton as of yet.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00944.html
Tassilo von Parseval has been working with the new MULTICALL interface
and noticed problems when the return stack is very large. This
shows up as segfaults in XS code, such as List::Util.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00958.html
Paul Green uses Perl on Stratus VOS, whose file system limits file
names to no more than 32 characters. This poses a problem when he
tries to run the test suite of a module like Pod::Simple, which
contains a test name search_25_glob_squaa_coloncolon_kleene.t.
At 40 characters long, that's more than Stratus can bear.
Similarly, there's another file, _white_with_navy_blue_on_black.css
that is also a bit too long. Nicholas Clark wondered whether
32 was some sort of POSIX minimum, and recalled that some tests
had already been renamed to deal with characters in file names that
VMS had trouble processing. Joshua Juran noted that traditional
Mac-based platforms (MacOS and Lamp) are limited to 31
characters. (MacOS X does not have this limitation).
(The Summariser wishes to point out the existence of
Sébastien Aperghis-Tramoni's Test::Portablility::Files
to module authors).
One file http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg01003.html
And then another http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg01004.html
No more excuses http://search.cpan.org/dist/Test-Portability-Files/
James Overly had problems building a 64-bit perl on Solaris 8.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00058.html
chromatic showed how the trick of assigning to the __ANON__
typeglob to name an anonymous subroutine doesn't work in the
debugger.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00147.html
O::Deparse not working as expected (#38684) "harleypig" was having trouble with split. I tried to pay attention,
but Stephen McCamant supplied a patch to fix the behaviour (which was
apparently broken), which was applied by Rafael. The end.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00202.html
1548 open items http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00193.html
in all their glory http://rt.perl.org/rt3/NoAuth/perl5/Overview.html
CPAN version 1.87 uploaded by Andreas Koenig.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00949.html
Archive::Tar version 1.29 uploaded by Jos I. Boumans.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00074.html
Seung-Ho Han wanted to know how make sense of what B::Xref::compile
produces. Joshua ben Jore explained what was going on, and that more
clues can be found by studying O.pm.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00952.html
Jerry Hedden started to extract threads.pm from the core in order to
make it available on CPAN. This would permit enhancements to be made to
the threads implementation faster than the current blead to maint
to release cycle.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg01013.html
Jim Cromie continued to refine his self-described hare-brained
op-next/op-siblingoptimisation scheme, defending it against
the critics, but ran into trouble somewhere deep down in the guts.
In doing so, he came up with a new presentation scheme for
B::Concise.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00001.html
Anton Berezin caught and eliminated an extraneous #endif in
fakesdio.h.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00010.html
Jarkko Hietaniemi discovered that -d:Foo=bar no longer works
in the current Perl release (bug report #38657). Rafael traced the
problem down to the fact that \0 (NUL) was no longer allowed in
environment variables, and fixed things up as change #27359. Jarkko
also supplied another patch for the same thing, which Rafael also
applied.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00025.html http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00052.html
Getting back to last week's thread on unwanted auto-vivification with
foreach , David Nicol showed a snippet of code that offers a way of
working around the problem, and wondered whether the documentation
should record it somewhere. Graham Barr noted that using reverse
also suppresses the auto-vivification behaviour. And that if you didn't
want a slice reversed, you needed to reverse reverse.
There's at least one way to do it http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00044.html
Jarkko added a test to Data::Dumper's test suite to ensure that the bug
#38612 that was fixed in 5.8.7 never returns.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00049.html
H.Merijn added Configure support for the GCC compiler options
__builtin_expect and __builtin_choose_expr .
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00063.html
Paul Marquess delivered a patch for Compress::Zlib , following on from
his recent work to add compression plugins.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00064.html
Joshua start to have a look at the new smart match operator ~~ and
found a discrepancy between its behaviour and that of Pugs/Perl6.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00081.html
Abe Timmerman patched Porting/checkcfgvar.pl to pick up configure.com and plunged unwittingly into the wonderful and frightening world of VMS symbols. John E. Malmberg and Craig A. Berry were sent in to rescue him.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00090.html
Abe then thought it would be a good idea to see what happens when one builds a threaded perl on VMS. In the process he uncovered a couple of problems that John and Craig sorted out.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00139.html
Dave Rolsky wanted to know if nested closures still leak memory. Dave
Mitchell thought that no closure leakage bugs remained in blead, but
pointed out that not all of the new code had made it back into maint.
Until proven otherwise http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00103.html
Randy W. Sims want to install an older perl on his Ubuntu linux distribution, but the install began to create an infinitely deep directory tree.
On and on and on http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00148.html
Linda W gave a report on the effects of configuration options on the resulting perl binary.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00161.html
Perl can no longer be compiled with a K&R compiler.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00160.html
David Nicol posted his thought on what he would like to see in the way of plug-in optimisers. A optimistic optimiser could optimise a section of code, and then, if some assumption failed to hold true, it could de-optimise the code back to the initial state. I think some proof-of-concept code will be required.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-03/msg00174.html
This summary was written by David Landgren.
Information concerning bugs referenced in this summary (as #nnnnn)
may be viewed at http://rt.perl.org/rt3/Ticket/Display.html?id=nnnnn
Information concerning patches to maint or blead referenced in
this summary (as #nnnnn) may be viewed at
http://public.activestate.com/cgi-bin/perlbrowse?patch=nnnnn
If you want a bookmarklet approach to viewing bugs and change reports, there are a couple of bookmarklets that you might find useful on my page of Perl stuff:
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