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[EP-tech] Re: Apache segfault

OK,

First of all try to remove the two plugins one at a time and in the meantime start apache to see which one breaks apache.

Building apache from sources is not very dramatic, you just have to find an "easy guide". I'll search later to see if I find any and I will come back with the link. Do you run any other sites through the same apache (which may use PHP, python or any other server side language)?

In order to check a binary's linked libraries you can do so using the ldd command followed by the full path of the binary. In my system (Debian), running ldd on the apache2 binary returns:

# ldd /usr/sbin/apache2
.    linux-vdso.so.1 (0x00007fff8bce5000)
    libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f6c588ad000)
    libaprutil-1.so.0 => /usr/lib/x86_64-linux-gnu/libaprutil-1.so.0 (0x00007f6c58684000)
    libapr-1.so.0 => /usr/lib/x86_64-linux-gnu/libapr-1.so.0 (0x00007f6c5844e000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f6c58231000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f6c57e88000)
    libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007f6c57c82000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f6c57a7a000)
    libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f6c57843000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f6c5763e000)
    libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f6c57415000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f6c58dc9000)

Moreover, to see how many versions of a library are installed in your system you can use ldconfig with the -p option. So for example in the same system:
# ldconfig -p | grep -i expat
    libexpatw.so.1 (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libexpatw.so.1
    libexpatw.so (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libexpatw.so
    libexpat.so.1 (libc6,x86-64) => /lib/x86_64-linux-gnu/libexpat.so.1
    libexpat.so (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libexpat.so

Using dpkg-query in a debian-based system (like Ubuntu), you can see which file is installed by which package, so in my system again:

# dpkg-query  -S /usr/lib/x86_64-linux-gnu/libexpatw.so
libexpat1-dev:amd64: /usr/lib/x86_64-linux-gnu/libexpatw.so

I see that libexpat1-dev package installed the library of libexpatw in it.

Maybe you can use these commands in your system to see what's wrong.

On 25/09/2015 01:01 μμ, Richard Jones wrote:
Hi George,
 

It would be good if you could provide the relevant apache logs. Moreover, if you uninstall the packages you mentioned you installed yesterday, does apache work OK?

I haven't tried yet, but I would expect so - it broke the instant I installed them!  I may back them out to confirm, but I need them installed for the XSLT import plugins to work.
 
In the link you provided it's talking about the expat library and I'm not sure the packages you've mentioned are related to that.

I'm not totally clear either, but they're both XML related, so seemed like a reasonable bet.
 
Nonetheless, what the link implies as a solution (IF this is your problem), is to install apache through sources so as to remove the double-linking with lib-expat.  

Hm, that's what I was afraid of :)  I'm not sure how to do that, or what it means to "remove the double-linking", so I'm hesitant to go down that route just yet.

Cheers,

Richard

 
 

George.


On 25/09/2015 12:03 μμ, Richard Jones wrote:
Hi Folks,

I think that I'm experiencing this error:

http://wiki.eprints.org/w/Troubleshooting#Apache_Crashes_with_a_segmentation_fault

Yesterday I installed libxml-libxml-perl and libxml-libxslt-perl to fix a problem with XSLT crosswalks not being loaded, and now I'm unable to restart apache.

I installed apache2 on my ubuntu system via the aptitude (so, not from source), and I installed eprints from source and manually installed the dependencies via aptitude.

The troubleshooting guide tells me what the problem might be, but doesn't have a fix - does anyone know how to resolve?

Cheers,

Richard

--

Richard Jones, 

Founder, Cottage Labs 
t: @richard_d_jones, @cottagelabs


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-- 
George Mamalakis

IT and Security Officer, 
Electrical and Computer Engineer (Aristotle Univ. of Thessaloniki),
PhD (Aristotle Univ. of Thessaloniki),
MSc (Imperial College of London)

School of Electrical and Computer Engineering
Aristotle University of Thessaloniki

phone number : +30 (2310) 994379

*** Options: http://mailman.ecs.soton.ac.uk/mailman/listinfo/eprints-tech
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--

Richard Jones, 

Founder, Cottage Labs 
t: @richard_d_jones, @cottagelabs


*** Options: http://mailman.ecs.soton.ac.uk/mailman/listinfo/eprints-tech
*** Archive: http://www.eprints.org/tech.php/
*** EPrints community wiki: http://wiki.eprints.org/
*** EPrints developers Forum: http://forum.eprints.org/



-- 
George Mamalakis

IT and Security Officer, 
Electrical and Computer Engineer (Aristotle Univ. of Thessaloniki),
PhD (Aristotle Univ. of Thessaloniki),
MSc (Imperial College of London)

School of Electrical and Computer Engineering
Aristotle University of Thessaloniki

phone number : +30 (2310) 994379