Couldn't compile CustomCommitCode codeblock ... panic: sv_setpvn called with negative strlen -2 at /usr/share/perl5/Devel/StackTrace.pm line 53

Michael_Mol · August 6, 2014, 4:46pm

First attempt at writing an RT scrip, and I’m getting a compile error
I can’t easily identify as a problem with my code. Googling around
finds “sv_setpvn called with negative strlen -2” in multiple results,
but none of them in StackTrace.pm, mostly a lot of stuff surrounding
Unicode.

Purpose of the snippet is to take some automated messages sent by HP
hardware monitoring tools and give the ticket something informational
in the subject.

Help?

Error message:

Couldn’t compile CustomCommitCode codeblock ‘# Find the message from
transactionobj->content # Set the subject to the message by using
ticketobj->SetSubject my $body = $self->TransactionObj->Content; open
my $fh ‘<’, $body or return 0; my $trapID = <$fh>; chomp $trapID;
<$fh>; my $messageLine = <$fh>; chomp $messageLine;
$self->TicketObj->SetSubject("$trapID – $messageLine); close $fh;’:
panic: sv_setpvn called with negative strlen -2 at
/usr/share/perl5/Devel/StackTrace.pm line 53.

Platform: Ubuntu 14.04, all updates applied.

Code snippet in question:

Begin code snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;

open my $fh ‘<’, $body or return 0;

my $trapID = <$fh>; chomp $trapID;
<$fh>;
my $messageLine = <$fh>; chomp $messageLine;

$self->TicketObj->SetSubject("$trapID – $messageLine);

close $fh;

End code snippet

:wq

Kevin_Falcone · August 6, 2014, 5:04pm

First attempt at writing an RT scrip, and I’m getting a compile error
I can’t easily identify as a problem with my code. Googling around
finds “sv_setpvn called with negative strlen -2” in multiple results,
but none of them in StackTrace.pm, mostly a lot of stuff surrounding
Unicode.

You’ve panic’ed perl.

I assume you’re on mod_perl.

Begin code snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;

open my $fh ‘<’, $body or return 0;

my $trapID = <$fh>; chomp $trapID;
<$fh>;
my $messageLine = <$fh>; chomp $messageLine;

$self->TicketObj->SetSubject("$trapID – $messageLine);

close $fh;

Why are you turning a perfectly good string into a file handle just to
read three lines? Split it on newlines or write a regexp.

-kevin

Michael_Mol · August 6, 2014, 6:13pm

First attempt at writing an RT scrip, and I’m getting a compile error
I can’t easily identify as a problem with my code. Googling around
finds “sv_setpvn called with negative strlen -2” in multiple results,
but none of them in StackTrace.pm, mostly a lot of stuff surrounding
Unicode.

You’ve panic’ed perl.

I assume you’re on mod_perl.

I take that as an instruction to switch away from mod_perl. OK, fine.

Begin code snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;

open my $fh ‘<’, $body or return 0;

my $trapID = <$fh>; chomp $trapID;
<$fh>;
my $messageLine = <$fh>; chomp $messageLine;

$self->TicketObj->SetSubject("$trapID – $messageLine);

close $fh;

Why are you turning a perfectly good string into a file handle just to
read three lines?

Well, frankly, I only want lines 1 and 3, and don’t care about line 2.
And I haven’t written any perl code in about six years. I remembered
the <> mechanism for reading lines, and that was simple enough.

Split it on newlines or write a regexp.

Is there a significant efficiency benefit, or is it a particular
question of idiomatic or stylistic code?

:wq

Michael_Mol · August 6, 2014, 6:39pm

First attempt at writing an RT scrip, and I’m getting a compile error
I can’t easily identify as a problem with my code. Googling around
finds “sv_setpvn called with negative strlen -2” in multiple results,
but none of them in StackTrace.pm, mostly a lot of stuff surrounding
Unicode.

You’ve panic’ed perl.

I assume you’re on mod_perl.

I take that as an instruction to switch away from mod_perl. OK, fine.

I’ve switched to fcgid, even ensured mod_perl was not being loaded by
apache. No change in error message.

Begin code snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;

open my $fh ‘<’, $body or return 0;

my $trapID = <$fh>; chomp $trapID;
<$fh>;
my $messageLine = <$fh>; chomp $messageLine;

$self->TicketObj->SetSubject("$trapID – $messageLine);

close $fh;

Why are you turning a perfectly good string into a file handle just to
read three lines?

Well, frankly, I only want lines 1 and 3, and don’t care about line 2.
And I haven’t written any perl code in about six years. I remembered
the <> mechanism for reading lines, and that was simple enough.

Split it on newlines or write a regexp.

Is there a significant efficiency benefit, or is it a particular
question of idiomatic or stylistic code?

Code snippet is now:

Begin snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;
my @lines = split(m/\n/, $body);
my $trapID = $lines[0];
my $message = $lines[2];

$self->TicketObj->SetSubject("$trapID – $message);

End snippet

No change in error message. (Whether using mod_perl or mod_fcgid.)

(Code is still readable, and more compact, so I suppose that’s nice.)

:wq

Alex_Vandiver · August 6, 2014, 8:16pm

Code snippet is now:

Begin snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;
my @lines = split(m/\n/, $body);
my $trapID = $lines[0];
my $message = $lines[2];

$self->TicketObj->SetSubject("$trapID – $message);

End snippet

You’re missing a closing double-quote on the last line. If that’s the
problem, it’s quite impressive that managed set panic perl – can you
show the output of perl -V ?

Alex

Michael_Mol · August 6, 2014, 8:28pm

Code snippet is now:

Begin snippet

Find the message from transactionobj->content

Set the subject to the message by using ticketobj->SetSubject

my $body = $self->TransactionObj->Content;
my @lines = split(m/\n/, $body);
my $trapID = $lines[0];
my $message = $lines[2];

$self->TicketObj->SetSubject("$trapID – $message);

End snippet

You’re missing a closing double-quote on the last line. If that’s the
problem, it’s quite impressive that managed set panic perl – can you
show the output of perl -V ?

Well, for the love of…that fixed it. (And cripes, how did I miss
that?) Anyway, thanks a ton; I was about to file a bug report on
Launchpad. I hate filing on Launchpad…

$ perl -V
Summary of my perl5 (revision 5 version 18 subversion 2) configuration:

Platform:
osname=linux, osvers=3.2.0-58-generic,
archname=x86_64-linux-gnu-thread-multi
uname=‘linux brownie 3.2.0-58-generic #88-ubuntu smp tue dec 3
17:37:58 utc 2013 x86_64 x86_64 x86_64 gnulinux ’
config_args=’-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN
-D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector --param=ssp-buffer-size=4
-Wformat -Werror=format-security -Dldflags= -Wl,-Bsymbolic-functions
-Wl,-z,relro -Dlddlflags=-shared -Wl,-Bsymbolic-functions -Wl,-z,relro
-Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr
-Dprivlib=/usr/share/perl/5.18 -Darchlib=/usr/lib/perl/5.18
-Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5
-Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local
-Dsitelib=/usr/local/share/perl/5.18.2
-Dsitearch=/usr/local/lib/perl/5.18.2 -Dman1dir=/usr/share/man/man1
-Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1
-Dsiteman3dir=/usr/local/man/man3 -Duse64bitint -Dman1ext=1
-Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh
-Ud_ualarm -Uusesfio -Uusenm -Ui_libutil -Uversiononly -DDEBUGGING=-g
-Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.18.2 -des’
hint=recommended, useposix=true, d_sigaction=define
useithreads=define, usemultiplicity=define
useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
use64bitint=define, use64bitall=define, uselongdouble=undef
usemymalloc=n, bincompat5005=undef
Compiler:
cc=‘cc’, ccflags =‘-D_REENTRANT -D_GNU_SOURCE -DDEBIAN
-fstack-protector -fno-strict-aliasing -pipe -I/usr/local/include
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64’,
optimize=‘-O2 -g’,
cppflags=‘-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fstack-protector
-fno-strict-aliasing -pipe -I/usr/local/include’
ccversion=‘’, gccversion=‘4.8.2’, 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=‘cc’, ldflags =’ -fstack-protector -L/usr/local/lib’
libpth=/usr/local/lib /lib/x86_64-linux-gnu /lib/…/lib
/usr/lib/x86_64-linux-gnu /usr/lib/…/lib /lib /usr/lib
libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
perllibs=-ldl -lm -lpthread -lc -lcrypt
libc=, so=so, useshrplib=true, libperl=libperl.so.5.18.2
gnulibc_version=‘2.19’
Dynamic Linking:
dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=‘-Wl,-E’
cccdlflags=‘-fPIC’, lddlflags=‘-shared -L/usr/local/lib -fstack-protector’

Characteristics of this binary (from libperl):
Compile-time options: HAS_TIMES MULTIPLICITY PERLIO_LAYERS
PERL_DONT_CREATE_GVSV
PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
PERL_IMPLICIT_CONTEXT PERL_MALLOC_WRAP
PERL_PRESERVE_IVUV PERL_SAWAMPERSAND USE_64_BIT_ALL
USE_64_BIT_INT USE_ITHREADS USE_LARGE_FILES
USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE
USE_LOCALE_NUMERIC USE_PERLIO USE_PERL_ATOF
USE_REENTRANT_API
Locally applied patches:
DEBPKG:debian/cpan_definstalldirs - Provide a sensible
INSTALLDIRS default for modules installed from CPAN.
DEBPKG:debian/db_file_ver - http://bugs.debian.org/340047
Remove overly restrictive DB_File version check.
DEBPKG:debian/doc_info - Replace generic man(1) instructions
with Debian-specific information.
DEBPKG:debian/enc2xs_inc - http://bugs.debian.org/290336 Tweak
enc2xs to follow symlinks and ignore missing @INC directories.
DEBPKG:debian/errno_ver - http://bugs.debian.org/343351 Remove
Errno version check due to upgrade problems with long-running
processes.
DEBPKG:debian/libperl_embed_doc -
http://bugs.debian.org/186778 Note that libperl-dev package is
required for embedded linking
DEBPKG:fixes/respect_umask - Respect umask during installation
DEBPKG:debian/writable_site_dirs - Set umask approproately for
site install directories
DEBPKG:debian/extutils_set_libperl_path - EU:MM: Set location
of libperl.a to /usr/lib
DEBPKG:debian/no_packlist_perllocal - Don’t install .packlist
or perllocal.pod for perl or vendor
DEBPKG:debian/prefix_changes - Fiddle with *PREFIX and
variables written to the makefile
DEBPKG:debian/fakeroot - Postpone LD_LIBRARY_PATH evaluation
to the binary targets.
DEBPKG:debian/instmodsh_doc - Debian policy doesn’t install
.packlist files for core or vendor.
DEBPKG:debian/ld_run_path - Remove standard libs from
LD_RUN_PATH as per Debian policy.
DEBPKG:debian/libnet_config_path - Set location of libnet.cfg
to /etc/perl/Net as /usr may not be writable.
DEBPKG:debian/mod_paths - Tweak @INC ordering for Debian
DEBPKG:debian/module_build_man_extensions -
http://bugs.debian.org/479460 Adjust Module::Build manual page
extensions for the Debian Perl policy
DEBPKG:debian/prune_libs - http://bugs.debian.org/128355 Prune
the list of libraries wanted to what we actually need.
DEBPKG:fixes/net_smtp_docs - [rt.cpan.org #36038]
http://bugs.debian.org/100195 Document the Net::SMTP ‘Port’ option
DEBPKG:debian/perlivp - http://bugs.debian.org/510895 Make
perlivp skip include directories in /usr/local
DEBPKG:debian/cpanplus_definstalldirs -
http://bugs.debian.org/533707 Configure CPANPLUS to use the site
directories by default.
DEBPKG:debian/cpanplus_config_path - Save local versions of
CPANPLUS::Config::System into /etc/perl.
DEBPKG:debian/deprecate-with-apt -
http://bugs.debian.org/702096 Point users to Debian packages of
deprecated core modules
DEBPKG:debian/squelch-locale-warnings -
http://bugs.debian.org/508764 Squelch locale warnings in Debian
package maintainer scripts
DEBPKG:debian/skip-upstream-git-tests - Skip tests specific to
the upstream Git repository
DEBPKG:debian/patchlevel - http://bugs.debian.org/567489 List
packaged patches for 5.18.2-2ubuntu1 in patchlevel.h
DEBPKG:debian/skip-kfreebsd-crash -
http://bugs.debian.org/628493 [perl #96272] Skip a crashing test case
in t/op/threads.t on GNU/kFreeBSD
DEBPKG:fixes/document_makemaker_ccflags -
http://bugs.debian.org/628522 [rt.cpan.org #68613] Document that
CCFLAGS should include $Config{ccflags}
DEBPKG:debian/find_html2text - http://bugs.debian.org/640479
Configure CPAN::Distribution with correct name of html2text
DEBPKG:debian/hurd_test_skip_stack -
http://bugs.debian.org/650175 Disable failing GNU/Hurd tests
dist/threads/t/stack.t
DEBPKG:fixes/manpage_name_Test-Harness -
http://bugs.debian.org/650451 [rt.cpan.org #73399] cpan/Test-Harness:
add NAME headings in modules with POD
DEBPKG:debian/makemaker-pasthru -
http://bugs.debian.org/660195 [rt.cpan.org #28632] Make EU::MM pass LD
through to recursive Makefile.PL invocations
DEBPKG:debian/perl5db-x-terminal-emulator.patch -
http://bugs.debian.org/668490 Invoke x-terminal-emulator rather than
xterm in perl5db.pl
DEBPKG:debian/cpan-missing-site-dirs -
http://bugs.debian.org/688842 Fix CPAN::FirstTime defaults with
nonexisting site dirs if a parent is writable
DEBPKG:fixes/memoize_storable_nstore - [rt.cpan.org #77790]
http://bugs.debian.org/587650 Memoize::Storable: respect ‘nstore’
option not respected
DEBPKG:fixes/net_ftp_failed_command - [rt.cpan.org #37700]
http://bugs.debian.org/491062 Net::FTP: cope gracefully with a failed
command
DEBPKG:fixes/perlbug-patchlist - [3541c11]
http://bugs.debian.org/710842 [perl #118433] Make perlbug look up the
list of local patches at run time
DEBPKG:fixes/module_metadata_security_doc - [68cdd4b]
CVE-2013-1437 documentation fix
DEBPKG:fixes/module_metadata_taint_fix - [bff978f]
http://bugs.debian.org/722210 [rt.cpan.org #88576] untaint version, if
needed, in Module::Metadata
DEBPKG:fixes/IPC-SysV-spelling - http://bugs.debian.org/730558
[rt.cpan.org #86736] Fix spelling of IPC_CREAT in IPC-SysV
documentation
DEBPKG:fixes/fix-undef-source -
Built under linux
Compiled at Mar 27 2014 18:30:28
@INC:
/etc/perl
/usr/local/lib/perl/5.18.2
/usr/local/share/perl/5.18.2
/usr/lib/perl5
/usr/share/perl5
/usr/lib/perl/5.18
/usr/share/perl/5.18
/usr/local/lib/site_perl
.

:wq