I have been using Request Tracker version 3 for quite sometime and it worked great. But suddenly the RT server crashed and the Apache error log had the below error message:
Attempt to free unreferenced scalar: SV 0x811ef70, Perl interpreter: 0x7f5a010 at /usr/lib/perl5/5.8.8/ExtUtils/Liblist.pm line 6. Segmentation fault
It seemed like many of the perl scripts had problems and in fact, the perl and cpan commands resulted with the same error as above:
# cpan Attempt to free unreferenced scalar: SV 0x811ef70, Perl interpreter: 0x7f5a010 at /usr/lib/perl5/5.8.8/ExtUtils/Liblist.pm line 6. Segmentation fault
Solution:
I was not sure what would have caused this error, but after spending sometime in Google, I understood that some of the perl modules or the operating system might have been updated. But the scary thing is, I didn’t update anything recently. Whatever, I started to troubleshoot the issue.
The only option I had was to install Perl and its modules again.
Re-install Perl
To be on a safer side, I took a backup of the old Perl installation files as below:
#mv /usr/lib/perl5 /usr/lib/perl5.bak #mv /usr/lib64/perl5 /usr/lib64/perl5.bak
Now, I re-installed Perl using Yum
#yum reinstall perl
Good, now I was able to execute at least the ‘perl‘ command (which I was not able to earlier)
# perl -v This is perl, v5.8.8 built for x86_64-linux-thread-multi
Install Perl CPAN
# perl -MCPAN -e shell Can't locate CPAN.pm in @INC (@INC contains:
I installed perl-CPAN module using yum
#yum install perl-CPAN
Now, the cpan also worked (without the segmentation fault error)
# cpan cpan shell -- CPAN exploration and modules installation (v1.7602) ReadLine support available (try 'install Bundle::CPAN') cpan>
Check if RT configurations are proper in httpd.conf
Below is the sample configuration:
NameVirtualHost rt_server:443 <VirtualHost rt_server:443> ServerName rt_server_in DocumentRoot /opt/rt3/share/html AddDefaultCharset UTF-8 PerlModule Apache::DBI PerlRequire "/opt/rt3/bin/webmux.pl" <Location /NoAuth/images> SetHandler default </Location> <Location /> SetHandler perl-script PerlResponseHandler RT::Mason </Location> ErrorLog logs/error_log SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP SSLEngine on SSLCertificateFile /etc/httpd/conf/ssl.crt/rt_server_cert.pem SSLCertificateKeyFile /etc/httpd/conf/ssl.key/rt_server_key.pem SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown downgrade-1.0 force-response-1.0 </VirtualHost>
Start httpd and mysqld server :
Remember, we haven’t installed any Perl module that are required to start RT. To know what are the perl modules required, we’ll start httpd server and solve the errors thrown in httpd error_log.
As expected, the ‘httpd‘ server failed to start and the error_log indicated that RT’s webmux.pl require the below modules:
Note: The httpd error_log will not provide all these module information at once, but it will hint which module is currently causing the issue. You’ll have to install one module at a time and try starting httpd service. If it fails, check error_log to find which module is the culprit (now!). Keep doing this step, until you find no error messages in error_log.
Below are the few modules I remembered to capture for writing this post. But you might have to install more….
Apache2/Response.pm Can't locate Log::Dispatch Params::Validate.pm Can't locate Module::Implementation Attribute::Handlers Can't locate File::ShareDir Can't locate Locale::Maketext::Lexicon [error] Base class package "Locale::Maketext::Fuzzy" is empty.\n (Perhaps you need to 'use' the module which defines that package first.)\n at /opt/rt3/bin/../lib/RT/I18N.pm line 62.\nBEGIN failed--compilation aborted at /opt/rt3/bin/../lib/RT/I18N.pm line 62.\nCompilation failed in require at /opt/rt3/bin/../lib/RT.pm line 152.\nBEGIN failed--compilation aborted at /opt/rt3/bin/webmux.pl line 102.\nCompilation failed in require at (eval 2) line 1.\n Can't locate MIME::Entity Can't locate DBIx::SearchBuilder Can't locate Email::Address Can't locate UNIVERSAL::require Text::Template Can't locate File::Slurp HTML::Element HTML::FormatText Font::Metrics::Courier Can't locate Text::Wrapper Time::ParseDate Test::EOL HTML::Scrubber Test/Memory/Cycle.pm Test/CPAN/Meta.pm Base class package "HTML::Mason::Request" is empty.\n install_driver(mysql) failed: Can't locate DBD/mysql.pm
Install Perl modules via CPAN
For example, if the httpd error_log reports : Can’t locate Log/Dispatch.pm @ INC….then you have to install that module via CPAN as below
cpan> install Log::Dispatch
Replace the above command to install other modules.
During the perl module installation, I landed up with version compatibility issue for DBD::MySQL module. The httpd error_log had the below message:
install_driver(mysql) failed: DBD::mysql object version 4.013 does not match bootstrap parameter 4.031
We have to move ‘mysql‘ folder under ‘/usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/auto/DBD‘ and ‘/usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/auto/DBI‘.
Now install ‘DBD::MySQL‘ module again via CPAN
cpan> install DBD::MySQL
Finally, the httpd server started and the error_log was clean without any messages. I tried accessing RT webpage via browser, to only see a dialog asking me to save a file ‘download‘. Ufff…what was that? I checked the httpd error_log and it didn’t have any message to help. All I did was to save the file ‘download’ from the browser and just opened it with a text editor. Fortunately, it had some message to help:
Can't located Apache/Session/MySQL.pm @ INC....
I installed ‘Apache/Session/
cpan > install Apache::Session::MySQL
RT webpage loaded without Style/CSS
After installing all the necessary Perl modules, I restarted the httpd server and tried accessing the RT webpage. The page loaded, but without any Style as below:
To fix the issue, you have to install a Perl module called ‘CSS:Squish‘
cpan > install CSS:Squish
That’s it. I was able to load RT webpage successfully. Hope this information might help someone out there.
You might also read : RT error : Mailgate undefined server error.
