From @exodist

Example reports​:
http​://www.cpantesters.org/cpan/report/c71f790c-62cf-11e7-a383-3a6add4d7def
http​://www.cpantesters.org/cpan/report/c9d1fa8a-62cf-11e7-a09b-166edd4d7def
http​://www.cpantesters.org/cpan/report/1d0446c4-62ec-11e7-99fd-83061003a64b

This module passes on perls 5.8.8 -> 5.26 so long as Test-Simple and
Test2-Suite are both up to date (there are some cpan failures related to
these being out of date, the 3 reports above are not due to old versions)

Strangely 5.8.1 fails with the exact same problems as 5.27.1, maybe a
regression?

From my own debugging I see 2 problems, they may be related​:

1) writes appear to happen out of order (that is we have multiple clones of
a filehandle, and we write to each clone, the on-disk copy does not reflect
the order of the print statements to the handles, even thought hey all have
autoflush set, are sent entire \n terminated lines, and point at the same
on-disk file)

2) PerlIO layers seem to be applied differently than they were before,
almost like applying one to STDOUT will also apply it to any pre-existing
clones of STDOUT, even if it did not previously (this is a guess).

Please note that there is a module all these load called
Test2​::Plugin​::OpenFixPerlIO which works around a perlio bug that appears
to have been fixed for 5.27.1, but changing things so that the module is
not loaded has no effect.

All these problems are related to PerlIO layers, the module itself uses
PerlIO layers to do its thing.

I tried to break this down into a minimal repro case, but was not able to
do so yet.

-Chad

Flags:
    category=core
    severity=low

Site configuration information for perl 5.27.1:

Configured by exodist at Fri Jul  7 08:37:46 PDT 2017.

Summary of my perl5 (revision 5 version 27 subversion 1) configuration:
___
  Platform:
    osname=linux
    osvers=4.11.7-1-arch
    archname=x86_64-linux-thread-multi
    uname='linux abydos 4.11.7-1-arch #1 smp preempt sat jun 24 09:07:09
cest 2017 x86_64 gnulinux '
    config_args='-de -Dprefix=/home/exodist/perl5/perlbrew/perls/5.27.1
-Dusethreads -Dusedevel
-Aeval:scriptdir=/home/exodist/perl5/perlbrew/perls/5.27.1/bin'
    hint=recommended
    useposix=true
    d_sigaction=define
    useithreads=define
    usemultiplicity=define
    use64bitint=define
    use64bitall=define
    uselongdouble=undef
    usemymalloc=n
    default_inc_excludes_dot=define
    bincompat5005=undef
  Compiler:
    cc='cc'
    ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe
-fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITS=64'
    optimize='-O2'
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe
-fstack-protector-strong -I/usr/local/include'
    ccversion=''
    gccversion='7.1.1 20170621'
    gccosandvers=''
    intsize=4
    longsize=8
    ptrsize=8
    doublesize=8
    byteorder=12345678
    doublekind=3
    d_longlong=define
    longlongsize=8
    d_longdbl=define
    longdblsize=16
    longdblkind=3
    ivtype='long'
    ivsize=8
    nvtype='double'
    nvsize=8
    Off_t='off_t'
    lseeksize=8
    alignbytes=8
    prototype=define
  Linker and Libraries:
    ld='cc'
    ldflags =' -fstack-protector-strong -L/usr/local/lib'
    libpth=/usr/local/lib
/usr/lib/gcc/x86_64-pc-linux-gnu/7.1.1/include-fixed /usr/lib /lib/../lib
/usr/lib/../lib /lib /lib64 /usr/lib64
    libs=-lpthread -lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc
-lgdbm_compat
    perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    libc=libc-2.25.so
    so=so
    useshrplib=false
    libperl=libperl.a
    gnulibc_version='2.25'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs
    dlext=so
    d_dlsymun=undef
    ccdlflags='-Wl,-E'
    cccdlflags='-fPIC'
    lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector-strong'

Locally applied patches:
    Devel::PatchPerl 1.38


@INC for perl 5.27.1:

/home/exodist/perl5/perlbrew/perls/5.27.1/lib/site_perl/5.27.1/x86_64-linux-thread-multi
    /home/exodist/perl5/perlbrew/perls/5.27.1/lib/site_perl/5.27.1

/home/exodist/perl5/perlbrew/perls/5.27.1/lib/5.27.1/x86_64-linux-thread-multi
    /home/exodist/perl5/perlbrew/perls/5.27.1/lib/5.27.1


Environment for perl 5.27.1:
    HOME=/home/exodist
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)

PATH=/home/exodist/perl5/perlbrew/bin:/home/exodist/perl5/perlbrew/perls/5.27.1/bin:/home/exodist/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
    PERLBREW_BASHRC_VERSION=0.78
    PERLBREW_HOME=/home/exodist/.perlbrew
    PERLBREW_MANPATH=/home/exodist/perl5/perlbrew/perls/5.27.1/man

PERLBREW_PATH=/home/exodist/perl5/perlbrew/bin:/home/exodist/perl5/perlbrew/perls/5.27.1/bin
    PERLBREW_PERL=5.27.1
    PERLBREW_ROOT=/home/exodist/perl5/perlbrew
    PERLBREW_VERSION=0.78
    PERL_BADLANG (unset)
    SHELL=/usr/bin/zsh

From @jkeenan

On Fri, 07 Jul 2017 20​:25​:57 GMT, exodist7@​gmail.com wrote​:

Example reports​:
http​://www.cpantesters.org/cpan/report/c71f790c-62cf-11e7-a383-
3a6add4d7def
http​://www.cpantesters.org/cpan/report/c9d1fa8a-62cf-11e7-a09b-
166edd4d7def
http​://www.cpantesters.org/cpan/report/1d0446c4-62ec-11e7-99fd-
83061003a64b

This module passes on perls 5.8.8 -> 5.26 so long as Test-Simple and
Test2-Suite are both up to date (there are some cpan failures related
to
these being out of date, the 3 reports above are not due to old
versions)

Strangely 5.8.1 fails with the exact same problems as 5.27.1, maybe a
regression?

From my own debugging I see 2 problems, they may be related​:

1) writes appear to happen out of order (that is we have multiple
clones of
a filehandle, and we write to each clone, the on-disk copy does not
reflect
the order of the print statements to the handles, even thought hey all
have
autoflush set, are sent entire \n terminated lines, and point at the
same
on-disk file)

2) PerlIO layers seem to be applied differently than they were before,
almost like applying one to STDOUT will also apply it to any pre-
existing
clones of STDOUT, even if it did not previously (this is a guess).

Please note that there is a module all these load called
Test2​::Plugin​::OpenFixPerlIO which works around a perlio bug that
appears
to have been fixed for 5.27.1, but changing things so that the module
is
not loaded has no effect.

All these problems are related to PerlIO layers, the module itself
uses
PerlIO layers to do its thing.

I tried to break this down into a minimal repro case, but was not able
to
do so yet.

-Chad

Here is the commit to blead which appears to have broken this CPAN module​:

#####
commit 99b8476
Author​: Tony Cook <tony@​develop-help.com>
AuthorDate​: Thu Jun 1 15​:11​:27 2017 +1000
Commit​: Tony Cook <tony@​develop-help.com>
CommitDate​: Wed Jun 7 11​:25​:59 2017 +1000

  [perl #131221] improve duplication of :via handles
 
  Previously duplication (as with open ... ">&...") would fail
  unless the user supplied a GETARG, which wasn't documented, and
  resulted in an attempt to free and unreferened scalar if supplied.
 
  Cloning on thread creation was simply broken.
 
  We now handle GETARG correctly, and provide a useful default if it
  returns nothing.
 
  Cloning on thread creation now duplicates the appropriate parts of the
  parent thread's handle.
#####

At the immediately preceding commit​:

#####
$ ./bin/perl -v | head -2 | tail -1
This is perl 5, version 27, subversion 1 (v5.27.1 (v5.27.0-141-g5d09ee1)) built for x86_64-linux
$ ./bin/cpanm --verbose Test2​::Plugin​::IOSync
...
Successfully installed Test2-Plugin-IOSync-0.000008
#####

At the breaking commit​:

#####
$ ./bin/perl -v | head -2 | tail -1
This is perl 5, version 27, subversion 1 (v5.27.1 (v5.27.0-142-g99b8476)) built for x86_64-linux
$ ./bin/cpanm --verbose Test2​::Plugin​::IOSync
...
Test Summary Report

t/IOEvents.t (Wstat​: 256 Tests​: 1 Failed​: 1)
  Failed test​: 1
  Non-zero exit status​: 1
t/IOEvents/Base.t (Wstat​: 512 Tests​: 3 Failed​: 2)
  Failed tests​: 2-3
  Non-zero exit status​: 2
t/IOEvents/STDERR.t (Wstat​: 512 Tests​: 3 Failed​: 2)
  Failed tests​: 2-3
  Non-zero exit status​: 2
t/IOEvents/STDOUT.t (Wstat​: 512 Tests​: 3 Failed​: 2)
  Failed tests​: 2-3
  Non-zero exit status​: 2
t/IOMuxer.t (Wstat​: 512 Tests​: 3 Failed​: 2)
  Failed tests​: 2-3
  Non-zero exit status​: 2
t/IOMuxer/Layer.t (Wstat​: 256 Tests​: 6 Failed​: 1)
  Failed test​: 6
  Non-zero exit status​: 1
t/IOSync.t (Wstat​: 768 Tests​: 5 Failed​: 3)
  Failed tests​: 3-5
  Non-zero exit status​: 3
t/OpenFixPerlIO.t (Wstat​: 768 Tests​: 13 Failed​: 3)
  Failed tests​: 1-2, 10
  Non-zero exit status​: 3
Files=8, Tests=37, 1 wallclock secs ( 0.03 usr 0.01 sys + 0.82 cusr 0.06 csys = 0.92 CPU)
Result​: FAIL
Failed 8/8 test programs. 16/37 subtests failed.
Makefile​:867​: recipe for target 'test_dynamic' failed
make​: *** [test_dynamic] Error 3
FAIL
#####

But note that in the test run above I got failures in 8 test files. The number of files with failures in at least one of the CPANtesters reports was only 3.

I haven't kept up with Test2 in the past two years, so I'm unfamiliar with the style of testing done in the failing files and cannot further diagnose the problem.

Thank you very much.
--
James E Keenan (jkeenan@​cpan.org)

The RT System itself - Status changed from 'new' to 'open'

From @exodist

Would it be possible to make it not diplicate the via layer when the getarg
is missing? I think part of the problem is that I do not want the layers to
dup with the handle.

On Jul 7, 2017 4​:26 PM, "James E Keenan via RT" <perlbug-followup@​perl.org>
wrote​:

On Fri, 07 Jul 2017 20​:25​:57 GMT, exodist7@​gmail.com wrote​:

Example reports​:
http​://www.cpantesters.org/cpan/report/c71f790c-62cf-11e7-a383-
3a6add4d7def
http​://www.cpantesters.org/cpan/report/c9d1fa8a-62cf-11e7-a09b-
166edd4d7def
http​://www.cpantesters.org/cpan/report/1d0446c4-62ec-11e7-99fd-
83061003a64b

This module passes on perls 5.8.8 -> 5.26 so long as Test-Simple and
Test2-Suite are both up to date (there are some cpan failures related
to
these being out of date, the 3 reports above are not due to old
versions)

Strangely 5.8.1 fails with the exact same problems as 5.27.1, maybe a
regression?

From my own debugging I see 2 problems, they may be related​:

1) writes appear to happen out of order (that is we have multiple
clones of
a filehandle, and we write to each clone, the on-disk copy does not
reflect
the order of the print statements to the handles, even thought hey all
have
autoflush set, are sent entire \n terminated lines, and point at the
same
on-disk file)

2) PerlIO layers seem to be applied differently than they were before,
almost like applying one to STDOUT will also apply it to any pre-
existing
clones of STDOUT, even if it did not previously (this is a guess).

Please note that there is a module all these load called
Test2​::Plugin​::OpenFixPerlIO which works around a perlio bug that
appears
to have been fixed for 5.27.1, but changing things so that the module
is
not loaded has no effect.

All these problems are related to PerlIO layers, the module itself
uses
PerlIO layers to do its thing.

I tried to break this down into a minimal repro case, but was not able
to
do so yet.

-Chad

Here is the commit to blead which appears to have broken this CPAN module​:

#####
commit 99b8476
Author​: Tony Cook <tony@​develop-help.com>
AuthorDate​: Thu Jun 1 15​:11​:27 2017 +1000
Commit​: Tony Cook <tony@​develop-help.com>
CommitDate​: Wed Jun 7 11​:25​:59 2017 +1000

\[perl \#131221\] improve duplication of :via handles

Previously duplication \(as with open \.\.\. ">&\.\.\."\) would fail
unless the user supplied a GETARG\, which wasn't documented\, and
resulted in an attempt to free and unreferened scalar if supplied\.

Cloning on thread creation was simply broken\.

We now handle GETARG correctly\, and provide a useful default if it
returns nothing\.

Cloning on thread creation now duplicates the appropriate parts of the
parent thread's handle\.

#####

At the immediately preceding commit​:

#####
$ ./bin/perl -v | head -2 | tail -1
This is perl 5, version 27, subversion 1 (v5.27.1 (v5.27.0-141-g5d09ee1))
built for x86_64-linux
$ ./bin/cpanm --verbose Test2​::Plugin​::IOSync
...
Successfully installed Test2-Plugin-IOSync-0.000008
#####

At the breaking commit​:

#####
$ ./bin/perl -v | head -2 | tail -1
This is perl 5, version 27, subversion 1 (v5.27.1 (v5.27.0-142-g99b8476))
built for x86_64-linux
$ ./bin/cpanm --verbose Test2​::Plugin​::IOSync
...
Test Summary Report
-------------------
t/IOEvents.t (Wstat​: 256 Tests​: 1 Failed​: 1)
Failed test​: 1
Non-zero exit status​: 1
t/IOEvents/Base.t (Wstat​: 512 Tests​: 3 Failed​: 2)
Failed tests​: 2-3
Non-zero exit status​: 2
t/IOEvents/STDERR.t (Wstat​: 512 Tests​: 3 Failed​: 2)
Failed tests​: 2-3
Non-zero exit status​: 2
t/IOEvents/STDOUT.t (Wstat​: 512 Tests​: 3 Failed​: 2)
Failed tests​: 2-3
Non-zero exit status​: 2
t/IOMuxer.t (Wstat​: 512 Tests​: 3 Failed​: 2)
Failed tests​: 2-3
Non-zero exit status​: 2
t/IOMuxer/Layer.t (Wstat​: 256 Tests​: 6 Failed​: 1)
Failed test​: 6
Non-zero exit status​: 1
t/IOSync.t (Wstat​: 768 Tests​: 5 Failed​: 3)
Failed tests​: 3-5
Non-zero exit status​: 3
t/OpenFixPerlIO.t (Wstat​: 768 Tests​: 13 Failed​: 3)
Failed tests​: 1-2, 10
Non-zero exit status​: 3
Files=8, Tests=37, 1 wallclock secs ( 0.03 usr 0.01 sys + 0.82 cusr
0.06 csys = 0.92 CPU)
Result​: FAIL
Failed 8/8 test programs. 16/37 subtests failed.
Makefile​:867​: recipe for target 'test_dynamic' failed
make​: *** [test_dynamic] Error 3
FAIL
#####

But note that in the test run above I got failures in 8 test files. The
number of files with failures in at least one of the CPANtesters reports
was only 3.

I haven't kept up with Test2 in the past two years, so I'm unfamiliar with
the style of testing done in the failing files and cannot further diagnose
the problem.

Thank you very much.
--
James E Keenan (jkeenan@​cpan.org)

---
via perlbug​: queue​: perl5 status​: new
https://rt-archive.perl.org/perl5/Ticket/Display.html?id=131716

From @exodist

I have found ways to mitigate all the breakages that do not involve changes to perl itself, and they do not break older versions. If nothing else is done for this task I should be ok.

That said, I want to propose that a via layer without a GETARGS should simply not be applied during cloning. Or at the very least make it so that a GETARGS that is present, but returns undef can implement that behavior.

From @jkeenan

On Sat, 08 Jul 2017 03​:25​:53 GMT, exodist7@​gmail.com wrote​:

I have found ways to mitigate all the breakages that do not involve
changes to perl itself, and they do not break older versions. If
nothing else is done for this task I should be ok.

Resolving ticket.

That said, I want to propose that a via layer without a GETARGS should
simply not be applied during cloning. Or at the very least make it so
that a GETARGS that is present, but returns undef can implement that
behavior.

Chad, if you would like to get discussion going about this, I'd suggest sending email to p5p with fresh discussion about it.

Thank you very much.
--
James E Keenan (jkeenan@​cpan.org)

@jkeenan - Status changed from 'open' to 'rejected'