Обсуждение: psql undefined symbol error on Ubuntu

Hello Friends,

I have installed postgres client on an Ubuntu machine. However, when I
try to run 'psql', I get this error message:

# psql
/usr/lib/postgresql/8.3/bin/psql: symbol lookup error:
/usr/local/lib/libreadline.so.5: undefined symbol: PC

Here is some information about the machine:
# uname -a
Linux hostname.domain.net 2.6.24-22-generic #1 SMP Mon Nov 24 19:35:06
UTC 2008 x86_64 GNU/Linux

Client installed: postgresql-client - front-end programs for PostgreSQL
(latest version)

Please let me know if more information is needed.

Thanks,
Harsha Hegde
Database Developer,
Vonage | 23 Main Street | Holmdel, NJ  07733
t: 732-203-7562
e: harshaDOThegdeATvonageDOTcom


NOTE: The information contained in this email message is considered
confidential and proprietary to the sender and is intended solely for
review and use by the named recipient.  Any unauthorized review, use or
distribution is strictly prohibited. If you have received this message
in error, please advise the sender by reply email and delete the
message.

"Harsha Hegde" <harsha.hegde@vonage.com> writes:
> I have installed postgres client on an Ubuntu machine. However, when I
> try to run 'psql', I get this error message:

> # psql
> /usr/lib/postgresql/8.3/bin/psql: symbol lookup error:
> /usr/local/lib/libreadline.so.5: undefined symbol: PC

This is a readline problem --- it's missing some underlying library,
probably libtermcap.

            regards, tom lane

On Thu, Jul 9, 2009 at 3:54 AM, Harsha Hegde<harsha.hegde@vonage.com> wrote:
>
> Hello Friends,
>
> I have installed postgres client on an Ubuntu machine. However, when I
> try to run 'psql', I get this error message:
>
> # psql
> /usr/lib/postgresql/8.3/bin/psql: symbol lookup error:
> /usr/local/lib/libreadline.so.5: undefined symbol: PC

Something has installed libreadline in /usr/local/lib (the one the PostgreSQL packages are supposed to use is in /lib),
andsomehow you have configured things so this version takes precedence over the system installed one. Possibly you
installedsome software that wasn't a Debian or Ubuntu package and it has damaged your system?
 



-- 
Stuart Bishop <stuart@stuartbishop.net>
http://www.stuartbishop.net/

Raghu Ram,

Thanks for responding. This link already seems to exist:

# ln -s /lib/libreadline.so.5 /lib/libedit.so.2
ln: creating symbolic link `/lib/libedit.so.2': File exists


Regards,
Harsha

NOTE: The information contained in this email message is considered
confidential and proprietary to the sender and is intended solely for
review and use by the named recipient. Any unauthorized review, use or
distribution is strictly prohibited. If you have received this message
in error, please advise the sender by reply email and delete the
message.





________________________________

From: raghu ram [mailto:raghuchennuru@gmail.com]
Sent: Wednesday, July 08, 2009 11:48 PM
To: Tom Lane
Cc: Harsha Hegde; pgsql-novice@postgresql.org
Subject: Re: [NOVICE] psql undefined symbol error on Ubuntu




On Thu, Jul 9, 2009 at 3:23 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:


    "Harsha Hegde" <harsha.hegde@vonage.com> writes:
    > I have installed postgres client on an Ubuntu machine.
However, when I
    > try to run 'psql', I get this error message:

    > # psql
    > /usr/lib/postgresql/8.3/bin/psql: symbol lookup error:
    > /usr/local/lib/libreadline.so.5: undefined symbol: PC


    This is a readline problem --- it's missing some underlying
library,
    probably libtermcap.

                           regards, tom lane



This is library missing error and you have to soft link with
libedit.so.2. use below command to soft link with library.

ln -s /lib/libreadline.so.5 /lib/libedit.so.2


Run the psql  as a postgres user,like
psql -d <database name> -p <port> -U <username>

Thanks & Regards,
Raghu Ram




    --
    Sent via pgsql-novice mailing list (pgsql-novice@postgresql.org)
    To make changes to your subscription:
    http://www.postgresql.org/mailpref/pgsql-novice

I meant to send this to the list:

Hi

2009/7/9 raghu ram <raghuchennuru@gmail.com>:
>
>
> On Thu, Jul 9, 2009 at 3:23 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>
>> "Harsha Hegde" <harsha.hegde@vonage.com> writes:
>> > I have installed postgres client on an Ubuntu machine. However, when I
>> > try to run 'psql', I get this error message:
>>
>> > # psql
>> > /usr/lib/postgresql/8.3/bin/psql: symbol lookup error:
>> > /usr/local/lib/libreadline.so.5: undefined symbol: PC
>>
>> This is a readline problem --- it's missing some underlying library,
>> probably libtermcap.
>>
>>                        regards, tom lane
>
> This is library missing error and you have to soft link with libedit.so.2.

This looks to me like the official Ubuntu postgresql-client-8.3
package.  It could, of course, be a third party package, but I think
that's unlikely based on where the psql command is installed.  Because
of this it was likely installed in the usual way with apt-get (or
similar), which would have made sure to install any required
dependencies, so it seems unlikely that the problem would be a missing
library or that libreadline.so.5 should be symlinked to libedit.so.2.

It's more likely that the version of libreadline.so.5 that ld.so finds
first on the library path is the wrong one.  This is especially
likely, since the one it appears to be finding is in /usr/local/lib
instead of where official Ubuntu packages install libraries (/lib or
/usr/lib).

> use below command to soft link with library.
>
> ln -s /lib/libreadline.so.5 /lib/libedit.so.2

That will have no effect here, because his "psql" is not using
/lib/readline.so.5.  It is trying to use
/usr/local/lib/libreadline.so.5 instead.

:)

--
Michael Wood <esiotrot@gmail.com>

I sent this directly to Harsha by mistake:

Hi

2009/7/8 Harsha Hegde <harsha.hegde@vonage.com>:
>
> Hello Friends,
>
> I have installed postgres client on an Ubuntu machine. However, when I
> try to run 'psql', I get this error message:
>
> # psql
> /usr/lib/postgresql/8.3/bin/psql: symbol lookup error:
> /usr/local/lib/libreadline.so.5: undefined symbol: PC

Google returns many results for the error
"/usr/local/lib/libreadline.so.5: undefined symbol: PC".  It is not
clear to me why so many people encounter this error, though.

By the way, why do you have a libreadline.so.5 in /usr/local/lib?
Official Ubuntu packages are never installed to /usr/local.  I think
the problem is that psql is finding the wrong libreadline.

What does this give you:
ldd /usr/lib/postgresql/8.3/bin/psql

In order to get psql to use the correct libreadline, you have several options.
1.)  Remove the one from /usr/local/lib and then run "ldconfig", but
this might break other things.  Since it should not have been
installed there by official Ubuntu packages, I hope you know what it
is that needs it and can decide if this is a problem.  If you try
this, first rename it to something else and see what breaks.  Then you
can rename it back again if necessary.

2.)  Configure ld.so.conf (or ld.so.conf.d/*) to ignore /usr/local/lib
(i.e. comment it out.  It should be in /etc/ld.so.conf.d/libc).  Then
run "ldconfig".  This is similar to option 1.  i.e. it could break
other things, but should not break any official Ubuntu packages.

3.)  Configure ld.so (same files as for option 2) so that /lib and
/usr/lib are before /usr/local/lib when you run "ldconfig -v".  Not
sure about this, but you might just be able to put them above
/usr/local/lib in /etc/ld.so.conf.d/libc.  This should be safe, but
keep a live CD handy in case.  Remember to run "ldconfig" after
changing the files.

4.)  Use LD_PRELOAD to force psql to use the correct libreadline.
This is the ugliest solution and you would have to do it every time
you run psql (or write a script that does this), so I don't recommend
it:

LD_PRELOAD=/lib/libreadline.so.5 psql

also, I haven't tested it.  It won't break anything and I'm pretty
sure it will work, but as I said, it's ugly.

The best solution, I think, is number 1, but only if you don't
actually need the version in /usr/local for some reason.

I hope this helps and is not too confusing :)

--
Michael Wood <esiotrot@gmail.com>

Michael Wood <esiotrot@gmail.com> writes:
> Google returns many results for the error
> "/usr/local/lib/libreadline.so.5: undefined symbol: PC".  It is not
> clear to me why so many people encounter this error, though.

Historically the problem with readline has been that it can function
with either of two underlying libraries (termcap or ncurses, if memory
serves) and somebody thought it would be a brilliant idea to postpone
the decision to runtime.  Which meant that instead of having a package
manager dependency on one or the other, libreadline packages were
shipped with no explicit dependency on *either*.  Everything was fine
if you actually had one of the two installed; if not, not so much.

Of course this approach is pretty idiotic in the context of modern
package-manager-based distributions.  Red Hat started forcing a choice
some years ago.  I'm not sure what Ubuntu does.  I suspect what the OP
has got is one of these ill-considered packages with no hard dependency;
but as you say, if it were an official Ubuntu package it wouldn't be
installing into /usr/local.

I don't have anything to add to your advice about how to fix it, just
wanted to shed a bit of light on why readline has got a history of this
kind of issue.

            regards, tom lane

2009/7/9 Tom Lane <tgl@sss.pgh.pa.us>:
> Michael Wood <esiotrot@gmail.com> writes:
>> Google returns many results for the error
>> "/usr/local/lib/libreadline.so.5: undefined symbol: PC".  It is not
>> clear to me why so many people encounter this error, though.
>
> Historically the problem with readline has been that it can function
> with either of two underlying libraries (termcap or ncurses, if memory
> serves) and somebody thought it would be a brilliant idea to postpone
> the decision to runtime.  Which meant that instead of having a package
> manager dependency on one or the other, libreadline packages were
> shipped with no explicit dependency on *either*.  Everything was fine
> if you actually had one of the two installed; if not, not so much.

OK, thanks for the explanation, but it still doesn't really explain
why so many people seem to have a broken libreadline in
/usr/*local*/lib :)

> Of course this approach is pretty idiotic in the context of modern
> package-manager-based distributions.  Red Hat started forcing a choice
> some years ago.  I'm not sure what Ubuntu does.  I suspect what the OP
> has got is one of these ill-considered packages with no hard dependency;
> but as you say, if it were an official Ubuntu package it wouldn't be
> installing into /usr/local.

Ubuntu appears to depend on libncurses:

$ apt-cache show libreadline5 | grep ^Depends
Depends: readline-common, libc6 (>= 2.6-1), libncurses5 (>= 5.6)

although dpkg supports dependencies which say that one package depends
on one of X or Y.

e.g. the dependencies for the gnome-desktop-environment package contains this:
totem-gstreamer (>= 2.22.2) | totem-xine (>= 2.22.2)

There's also another way to do this sort of thing.  Packages can say
what they provide, and that can be basically the name of the package,
or a sort of virtual package.  e.g. all MTAs on Debian and Ubuntu
provide "mail-transport-agent":

$ apt-cache show exim4-daemon-light | grep ^Provides
Provides: exim4-localscanapi-1.0, exim4-localscanapi-1.1, mail-transport-agent

so if another package depends on an MTA, but doesn't care which one,
it can just depend on mail-transport-agent.

I seem to remember RPM also supports this, so I don't see why anyone
would have decided not to depend on either one, unless it was possible
to use some of the functionality of libreadline without needing
ncurses or termcap.

> I don't have anything to add to your advice about how to fix it, just
> wanted to shed a bit of light on why readline has got a history of this
> kind of issue.

Thanks :)

--
Michael Wood <esiotrot@gmail.com>

Thanks to all for the responses. Systems Ops has resolved this issue. I am able to successfully connect.


Thanks,
Harsha Hegde
Database Developer,
 Vonage| 23 Main Street | Holmdel, NJ  07733
t: 732-203-7562
e: harshaDOThegdeATvonage.com
location: D1-A161

NOTE: The information contained in this email message is considered confidential and proprietary to the sender and is
intendedsolely for review and use by the named recipient.  Any unauthorized review, use or distribution is strictly
prohibited.If you have received this message in error, please advise the sender by reply email and delete the message. 







-----Original Message-----
From: pgsql-novice-owner@postgresql.org [mailto:pgsql-novice-owner@postgresql.org] On Behalf Of Michael Wood
Sent: Thursday, July 09, 2009 1:10 PM
To: Tom Lane
Cc: pgsql-novice@postgresql.org
Subject: Re: [NOVICE] psql undefined symbol error on Ubuntu

2009/7/9 Tom Lane <tgl@sss.pgh.pa.us>:
> Michael Wood <esiotrot@gmail.com> writes:
>> Google returns many results for the error
>> "/usr/local/lib/libreadline.so.5: undefined symbol: PC".  It is not
>> clear to me why so many people encounter this error, though.
>
> Historically the problem with readline has been that it can function
> with either of two underlying libraries (termcap or ncurses, if memory
> serves) and somebody thought it would be a brilliant idea to postpone
> the decision to runtime.  Which meant that instead of having a package
> manager dependency on one or the other, libreadline packages were
> shipped with no explicit dependency on *either*.  Everything was fine
> if you actually had one of the two installed; if not, not so much.

OK, thanks for the explanation, but it still doesn't really explain why so many people seem to have a broken
libreadlinein /usr/*local*/lib :) 

> Of course this approach is pretty idiotic in the context of modern
> package-manager-based distributions.  Red Hat started forcing a choice
> some years ago.  I'm not sure what Ubuntu does.  I suspect what the OP
> has got is one of these ill-considered packages with no hard
> dependency; but as you say, if it were an official Ubuntu package it
> wouldn't be installing into /usr/local.

Ubuntu appears to depend on libncurses:

$ apt-cache show libreadline5 | grep ^Depends
Depends: readline-common, libc6 (>= 2.6-1), libncurses5 (>= 5.6)

although dpkg supports dependencies which say that one package depends on one of X or Y.

e.g. the dependencies for the gnome-desktop-environment package contains this:
totem-gstreamer (>= 2.22.2) | totem-xine (>= 2.22.2)

There's also another way to do this sort of thing.  Packages can say what they provide, and that can be basically the
nameof the package, or a sort of virtual package.  e.g. all MTAs on Debian and Ubuntu provide "mail-transport-agent": 

$ apt-cache show exim4-daemon-light | grep ^Provides
Provides: exim4-localscanapi-1.0, exim4-localscanapi-1.1, mail-transport-agent

so if another package depends on an MTA, but doesn't care which one, it can just depend on mail-transport-agent.

I seem to remember RPM also supports this, so I don't see why anyone would have decided not to depend on either one,
unlessit was possible to use some of the functionality of libreadline without needing ncurses or termcap. 

> I don't have anything to add to your advice about how to fix it, just
> wanted to shed a bit of light on why readline has got a history of
> this kind of issue.

Thanks :)

--
Michael Wood <esiotrot@gmail.com>

--
Sent via pgsql-novice mailing list (pgsql-novice@postgresql.org) To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-novice

For the sake of information, Systems had installed a customized version of the readline (I don't know what was
customized),which was the cause of conflict. Once that was removed, everything worked fine.  

Regards,
Harsha

NOTE: The information contained in this email message is considered confidential and proprietary to the sender and is
intendedsolely for review and use by the named recipient. Any unauthorized review, use or distribution is strictly
prohibited.If you have received this message in error, please advise the sender by reply email and delete the message. 




-----Original Message-----
From: Harsha Hegde
Sent: Thursday, July 09, 2009 3:50 PM
To: pgsql-novice@postgresql.org
Subject: RE: [NOVICE] psql undefined symbol error on Ubuntu

Thanks to all for the responses. Systems Ops has resolved this issue. I am able to successfully connect.


Thanks,
Harsha Hegde
Database Developer,
 Vonage| 23 Main Street | Holmdel, NJ  07733
t: 732-203-7562
e: harshaDOThegdeATvonage.com
location: D1-A161

NOTE: The information contained in this email message is considered confidential and proprietary to the sender and is
intendedsolely for review and use by the named recipient.  Any unauthorized review, use or distribution is strictly
prohibited.If you have received this message in error, please advise the sender by reply email and delete the message. 







-----Original Message-----
From: pgsql-novice-owner@postgresql.org [mailto:pgsql-novice-owner@postgresql.org] On Behalf Of Michael Wood
Sent: Thursday, July 09, 2009 1:10 PM
To: Tom Lane
Cc: pgsql-novice@postgresql.org
Subject: Re: [NOVICE] psql undefined symbol error on Ubuntu

2009/7/9 Tom Lane <tgl@sss.pgh.pa.us>:
> Michael Wood <esiotrot@gmail.com> writes:
>> Google returns many results for the error
>> "/usr/local/lib/libreadline.so.5: undefined symbol: PC".  It is not
>> clear to me why so many people encounter this error, though.
>
> Historically the problem with readline has been that it can function
> with either of two underlying libraries (termcap or ncurses, if memory
> serves) and somebody thought it would be a brilliant idea to postpone
> the decision to runtime.  Which meant that instead of having a package
> manager dependency on one or the other, libreadline packages were
> shipped with no explicit dependency on *either*.  Everything was fine
> if you actually had one of the two installed; if not, not so much.

OK, thanks for the explanation, but it still doesn't really explain why so many people seem to have a broken
libreadlinein /usr/*local*/lib :) 

> Of course this approach is pretty idiotic in the context of modern
> package-manager-based distributions.  Red Hat started forcing a choice
> some years ago.  I'm not sure what Ubuntu does.  I suspect what the OP
> has got is one of these ill-considered packages with no hard
> dependency; but as you say, if it were an official Ubuntu package it
> wouldn't be installing into /usr/local.

Ubuntu appears to depend on libncurses:

$ apt-cache show libreadline5 | grep ^Depends
Depends: readline-common, libc6 (>= 2.6-1), libncurses5 (>= 5.6)

although dpkg supports dependencies which say that one package depends on one of X or Y.

e.g. the dependencies for the gnome-desktop-environment package contains this:
totem-gstreamer (>= 2.22.2) | totem-xine (>= 2.22.2)

There's also another way to do this sort of thing.  Packages can say what they provide, and that can be basically the
nameof the package, or a sort of virtual package.  e.g. all MTAs on Debian and Ubuntu provide "mail-transport-agent": 

$ apt-cache show exim4-daemon-light | grep ^Provides
Provides: exim4-localscanapi-1.0, exim4-localscanapi-1.1, mail-transport-agent

so if another package depends on an MTA, but doesn't care which one, it can just depend on mail-transport-agent.

I seem to remember RPM also supports this, so I don't see why anyone would have decided not to depend on either one,
unlessit was possible to use some of the functionality of libreadline without needing ncurses or termcap. 

> I don't have anything to add to your advice about how to fix it, just
> wanted to shed a bit of light on why readline has got a history of
> this kind of issue.

Thanks :)

--
Michael Wood <esiotrot@gmail.com>

--
Sent via pgsql-novice mailing list (pgsql-novice@postgresql.org) To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-novice