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<div class="moz-cite-prefix">Hmm, OK,<br>
<br>
I read the site behind the link a bit more carefully and it seems
that this is your problem indeed. You can verify it by checking
the apache2 and mod_perl binaries and see if they're both linked
with expat. Eg, run:<br>
<br>
# ldd /usr/bin/apache2 | grep -i expat<br>
# ldd /usr/lib/apache2/modules/mod_perl.so | grep -i expat<br>
<br>
and you should only see only one of them returning a link with the
expat library. If both return it, then it seems that this is your
case indeed.<br>
<br>
In that case, you'll have to build apache from source if you want
to collocate apache and XML::Parser for perl. There's this guide
for building apache2.4 for Ubuntu (!!<b>not</b> 2.2!!), but from
what I see all apache dependencies are installed (as it says) from
apache2 package, so there might be a problem with linking to
libexpat as well
(<a class="moz-txt-link-freetext" href="http://phpboyscout.uk/compiling-apache-2-4-ubuntu-12-04/">http://phpboyscout.uk/compiling-apache-2-4-ubuntu-12-04/</a>). On the
other hand, linking is mainly performed based on what the
configure script instructs, so at that point you should probably
remove some of it's flags that cause this linkage, but I'm not
sure which. But I'm not sure where the problem comes from: should
apache be built without expat support or mod_perl? Because this is
not clear from the wiki<br>
<br>
I've done a small research with problems related to apache and
lib-expat and in another situation (which seems very similar) that
involved apache and mod_wsgi the problem was that the two
installed expat libraries had different versions that caused
apache to crash (because it was calling some library function with
a different prototype, most probably). You can check each expat
version by running something like:<br>
<br>
# strings /path/to/your/libexpat/binary | grep expat_ <br>
<br>
and you'll most probably find out that the versions differ. The
solution would be for both binaries to use the same expat library,
which theoretically can be achieved by LD_PRELOAD, so maybe you
could start the apache binary from command line using something
like:<br>
<br>
# LD_PRELOAD=/path/to/mod_perls/expat/library /usr/sbin/apachectl
start<br>
<br>
In that case it may work...but this means that you cannot start or
stop apache using Ubuntu's startup scripts, except if Ubuntu has a
way of telling which libraries should be preloaded before
executing the apache binary (which is way out of my knowledge,
since I'm mostly a BSD guy).<br>
<br>
I'm not sure if I helped...:)<br>
<br>
On 25/09/2015 02:07 μμ, George Mamalakis wrote:<br>
</div>
<blockquote
cite="mid:EMEW3|92098043b6574f30c354ea0cb3c82841r8OC8814eprints-tech-bounces|ecs.soton.ac.uk|56052AE0.9060006@eng.auth.gr"
type="cite">
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<div class="moz-cite-prefix">OK,<br>
<br>
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.<br>
<br>
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)?<br>
<br>
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:<br>
<br>
# ldd /usr/sbin/apache2<br>
. linux-vdso.so.1 (0x00007fff8bce5000)<br>
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3
(0x00007f6c588ad000)<br>
libaprutil-1.so.0 =>
/usr/lib/x86_64-linux-gnu/libaprutil-1.so.0 (0x00007f6c58684000)<br>
libapr-1.so.0 => /usr/lib/x86_64-linux-gnu/libapr-1.so.0
(0x00007f6c5844e000)<br>
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0
(0x00007f6c58231000)<br>
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
(0x00007f6c57e88000)<br>
libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1
(0x00007f6c57c82000)<br>
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1
(0x00007f6c57a7a000)<br>
libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1
(0x00007f6c57843000)<br>
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2
(0x00007f6c5763e000)<br>
libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1
(0x00007f6c57415000)<br>
/lib64/ld-linux-x86-64.so.2 (0x00007f6c58dc9000)<br>
<br>
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:<br>
# ldconfig -p | grep -i expat<br>
libexpatw.so.1 (libc6,x86-64) =>
/usr/lib/x86_64-linux-gnu/libexpatw.so.1<br>
libexpatw.so (libc6,x86-64) =>
/usr/lib/x86_64-linux-gnu/libexpatw.so<br>
libexpat.so.1 (libc6,x86-64) =>
/lib/x86_64-linux-gnu/libexpat.so.1<br>
libexpat.so (libc6,x86-64) =>
/usr/lib/x86_64-linux-gnu/libexpat.so<br>
<br>
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:<br>
<br>
# dpkg-query -S /usr/lib/x86_64-linux-gnu/libexpatw.so<br>
libexpat1-dev:amd64: /usr/lib/x86_64-linux-gnu/libexpatw.so<br>
<br>
I see that libexpat1-dev package installed the library of
libexpatw in it.<br>
<br>
Maybe you can use these commands in your system to see what's
wrong.<br>
<br>
On 25/09/2015 01:01 μμ, Richard Jones wrote:<br>
</div>
<blockquote
cite="mid:EMEW3|7b3d7c76fca8fde575faa848a9b2cbacr8OB2Y14eprints-tech-bounces|ecs.soton.ac.uk|CAJaHgurVYMDKLWsSHm2yj=q4_eyuqphabXnZLs03ojwbMKtEbg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div>Hi George,</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div> <br>
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?</div>
</div>
</blockquote>
<div><br>
</div>
<div>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.</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div> 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. </div>
</div>
</blockquote>
<div><br>
</div>
<div>I'm not totally clear either, but they're both XML
related, so seemed like a reasonable bet.</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div>Nonetheless, what the link implies as a solution
(<b>IF</b> this is your problem), is to install
apache through sources so as to remove the
double-linking with lib-expat. </div>
</div>
</blockquote>
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div>Cheers,</div>
<div><br>
</div>
<div>Richard</div>
<div><br>
</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div> <br>
<br>
George.
<div>
<div class="h5"><br>
<br>
On 25/09/2015 12:03 μμ, Richard Jones wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div class="h5">
<div dir="ltr">
<div>Hi Folks,</div>
<div><br>
</div>
<div>I think that I'm experiencing this error:</div>
<div><br>
</div>
<a moz-do-not-send="true"
href="http://wiki.eprints.org/w/Troubleshooting#Apache_Crashes_with_a_segmentation_fault"
target="_blank">http://wiki.eprints.org/w/Troubleshooting#Apache_Crashes_with_a_segmentation_fault</a><br
clear="all">
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div>The troubleshooting guide tells me what
the problem might be, but doesn't have a fix
- does anyone know how to resolve?</div>
<div><br>
</div>
<div>Cheers,</div>
<div><br>
</div>
<div>Richard</div>
<div><br>
</div>
-- <br>
<div>
<div><br>
</div>
Richard Jones,
<div><br>
</div>
<div>Founder, Cottage Labs
<div>t: @richard_d_jones, @cottagelabs</div>
<div>w: <a moz-do-not-send="true"
href="http://cottagelabs.com"
target="_blank">http://cottagelabs.com</a><br>
<div><br>
</div>
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<br>
<pre cols="72">--
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
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</div>
-- <br>
<div class="gmail_signature">
<div><br>
</div>
Richard Jones,
<div><br>
</div>
<div>Founder, Cottage Labs
<div>t: @richard_d_jones, @cottagelabs</div>
<div>w: <a moz-do-not-send="true"
href="http://cottagelabs.com" target="_blank">http://cottagelabs.com</a><br>
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<br>
<pre class="moz-signature" cols="72">--
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
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<br>
<pre class="moz-signature" cols="72">--
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
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