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Re: glibc + libstdc++?

On Monday 07 June 2004 12:06 pm, Bob Proulx wrote:
>Jeff Elkins wrote:
>> Bob Proulx wrote:
>> > Jeff Elkins wrote:
>> > > pvconv: relocation error: pvconv: undefined symbol: __dynamic_cast_2
>> >
>> > I was curious enough to download the application and try it.  I can
>> > get a usage string out of it so I think I have all of the libraries on
>> > my woody system.  I got a usage string out of it on a sid system.
>> [...]
>>  libstdc++-libc6.2-2.so.3 => /usr/lib/libstdc++-libc6.2-2.so.3
>> (0x40029000) [...]
>> dpkg -S /usr/lib/libstdc++-libc6.2-2.so.3
>> libstdc++2.10-glibc2.2: /usr/lib/libstdc++-libc6.2-2.so.3
>> [...]
>> Yep, I get a usage string, it just crashes when I try to use the app
>> <grrr> :)
>One of the things I am very interested in is cross distro
>compatibility.  So I ran the binary on a RH7.3 machine.  I just ran it
>against a random .wav file and it appeared that it runs there.  It
>gave me error messages about the conversion but did not report the
>missing symbol __dynamic_cast_2.
>Then I copied the library from the RH machine to my Debian woody
>machine.  I did not remove the debian package first.  Too many things
>depend up it.
>  apt-cache showpkg libstdc++2.10-glibc2.2
>But it is not required for basic C programs which make up the core
>utilities.  That is I won't break 'mv' by doing this like I could
>moving other libs around.
>Therefore I moved my debian version of the library out of the way and
>moved the RH version into place directly.  With that copied into place
>on Debian the pvconv program ran the same on my Debian machine as it
>did on the RH machine.  With this library in place I think the program
>will run.
>  cd /usr/lib
>  mv libstdc++-3-libc6.2-2-2.10.0.so libstdc++-3-libc6.2-2-2.10.0.so.debian
>  cp libstdc++-3-libc6.2-2-2.10.0.so.redhat libstdc++-3-libc6.2-2-2.10.0.so
>Warning: I really can't recommend this type of low level shared
>library manipulation.  Mistakes can really cause trouble with your
>system.  You can definitely break your system and need to boot a
>recovery image to repair it.  This is not the way to manage a system
>in production for example.  But for debugging this type of hacking can
>be useful.  And for your particular problem you might find this useful
>enough to solve your problem as much as you need it to be solved.
>I found an rpm of the library here:
> http://www.rpmfind.net//linux/RPM/redhat/7.3/updates/i386/libstdc++-2.96-11
>That can be unpacked using:
>  rpm2cpio libstdc++-2.96-113.i386.rpm | cpio -idm
>I see this solution as only a workaround.  The real solution would be
>to understand what RH did to their library which breaks compatibility,
>or the reverse.  Then modify the Debian version so that it works there

Yippee!!  It works :)

Thank you, thank you :)

I set up a script to swap the libs, run the converter, then swap them back so 
as not to leave my system in an unstable state. Goodbye Windows!


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