Distrbuted Debugging. Or - "Dear Lazy.pm, plz help track down this intermittent failure"

Nicholas Clark nick at ccl4.org
Wed Nov 12 22:30:10 GMT 2008


On Wed, Nov 12, 2008 at 09:20:34PM +0000, David Cantrell wrote:
> [I'm largely repeating stuff from IRC here - but some notes at the
> bottom about the new CPAN-testers website may be useful for everyone]
> 
> On Wed, Nov 12, 2008 at 06:50:10PM +0000, Simon Wistow wrote:
> 

> > So, if anybody can reproduce it reliably then please tell me

t/00-compile................ok   
t/01-parse..................1/75 
#   Failed test at t/01-parse.t line 39.
#          got: ''
#     expected: 'en-us'
# Looks like you failed 1 test of 75.
t/01-parse.................. Dubious, test returned 1 (wstat 256, 0x100)
 Failed 1/75 subtests 
t/02-create.................1/72 
#   Failed test 'feed language is correct'
#   at t/02-create.t line 24.
#          got: ''
#     expected: 'en_US'
# Looks like you failed 1 test of 72.
t/02-create................. Dubious, test returned 1 (wstat 256, 0x100)
 Failed 1/72 subtests 

t/11-xml-base-atom..........1/13 
#   Failed test 'Got feed base'
#   at t/11-xml-base-atom.t line 11.
#          got: ''
#     expected: 'http://example.org/'

#   Failed test 'Got entry base'
#   at t/11-xml-base-atom.t line 12.
#          got: ''
#     expected: 'http://example.org/archives/'

#   Failed test 'Got content base'
#   at t/11-xml-base-atom.t line 13.
#          got: ''
#     expected: 'http://example.org/archives/000001.html'

#   Failed test 'Got feed base'
#   at t/11-xml-base-atom.t line 20.
#          got: ''
#     expected: 'http://example.org/'

#   Failed test 'Got entry base'
#   at t/11-xml-base-atom.t line 21.
#          got: ''
#     expected: 'http://example.org/archives/'

#   Failed test 'Got content base'
#   at t/11-xml-base-atom.t line 22.
#          got: ''
#     expected: 'http://example.org/archives/000001.html'

#   Failed test 'Set feed base'
#   at t/11-xml-base-atom.t line 25.

#   Failed test 'Set entry base'
#   at t/11-xml-base-atom.t line 26.

#   Failed test 'Got feed base'
#   at t/11-xml-base-atom.t line 29.
#          got: ''
#     expected: 'http://foo.com/'

#   Failed test 'Got entry base'
#   at t/11-xml-base-atom.t line 30.
#          got: ''
#     expected: 'http://foo.com/archives/'
# Looks like you failed 10 tests of 13.
t/11-xml-base-atom.......... Dubious, test returned 10 (wstat 2560, 0xa00)
 Failed 10/13 subtests 

> > 
> > 1) What versions of XML::Atom, XML::RSS and XML::LibXML you're running

XML::Atom 0.29, but I had to force install it, as it failed tests just like

http://www.nntp.perl.org/group/perl.cpan.testers/2008/11/msg2595696.html

XML::RSS 1.36
XML::LibXML 1.68

> > 2) What your Perl -V is 

Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=linux, osvers=2.6.18-xenu, archname=x86_64-linux
    uname='linux zazen 2.6.18-xenu #1 smp thu oct 4 12:23:41 bst 2007 x86_64 gnulinux '
    config_args='-Dcc=ccache gcc -Dld=gcc -Dprefix=~/Sandpit/588 -de'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=define use64bitall=define uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='ccache gcc', ccflags ='-fno-strict-aliasing -pipe -Wdeclaration-after-statement -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-g',
    cppflags='-fno-strict-aliasing -pipe -Wdeclaration-after-statement -I/usr/local/include'
    ccversion='', gccversion='4.1.2 20061115 (prerelease) (Debian 4.1.1-21)', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -ldb -ldl -lm -lcrypt -lutil -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.3.6.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.3.6'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'


Characteristics of this binary (from libperl): 
  Compile-time options: PERL_MALLOC_WRAP USE_64_BIT_ALL USE_64_BIT_INT
                        USE_LARGE_FILES USE_PERLIO
  Built under linux
  Compiled at Oct  1 2008 17:03:45
  @INC:
    /home/nick/Sandpit/588/lib/perl5/5.8.8/x86_64-linux
    /home/nick/Sandpit/588/lib/perl5/5.8.8
    /home/nick/Sandpit/588/lib/perl5/site_perl/5.8.8/x86_64-linux
    /home/nick/Sandpit/588/lib/perl5/site_perl/5.8.8
    /home/nick/Sandpit/588/lib/perl5/site_perl
    .

> > 3) Whether the failure occurs with earlier versions of XML::Feed other 
> >    than 0.3 (specifically 0.23, 0.22 and 0.20) 

0.23 same fail
0.22 same fail
0.20 same fail


I can't find a version of XML::Atom that passes its tests for that build.
So I assume that one of its dependencies has changed the world underneath it.
It might be that the same change is affecting XML::Feed directly, or it
might be that it's indirect via a change in XML::Atom's behaviour. I don't
know. But to me it feels better to start with working out what is the cause
of XML::Atom's problem.

> > [*] Two example failures
> > http://www.nntp.perl.org/group/perl.cpan.testers/2008/11/msg2551035.html
> > http://www.nntp.perl.org/group/perl.cpan.testers/2008/11/msg2552599.html
> > 
> > note that both are patched to level 34559 although that seems unlikely 
> > to be the cause
> > 
> > http://public.activestate.com/cgi-bin/perlbrowse/p/34559
> 
> Ignoring that one bogus test result above, the only recent failures are
> those two.  This doesn't mean that change 34559 is to blame though, just
> that something between 5.8.8 and change 34559 is what dunnit.

> Barbie put a lot of work into this shiny new thing, he deserves a beer
> from every single one of you.

Guinness. Which may or may not be "beer" in your lexicon.


But anyway, I can reproduce it with 5.8.8, so it's not a 5.8.9-RC1
regression. I can sleep soundly now, safely inside my S.E.P. field.

Nicholas Clark


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