Centos 8 Support

[Jedediah Smith]

Hello,
Trying to get mrViewer v6.1.6 working on RHEL / Rocky 8.6. I get the following error:

```/opt/mrviewer/mrviewer//bin/mrViewer: /opt/mrviewer/mrviewer//lib/libp11-kit.so.0: no version information available (required by /opt/mrviewer/mrviewer//lib/libgnutls.so.30)
/opt/mrviewer/mrviewer//bin/mrViewer: symbol lookup error: /opt/mrviewer/mrviewer//lib/libgnutls.so.30: undefined symbol: asn1_der_decoding2, version LIBTASN1_0_3

I believe I've tracked it down to `libgnutls.so` - it seems like there are two dynamic links to different versions of the library

cd /path/to/mrviewer/bin
export LD_LIBRARY_PATH=../lib
ldd mrViewer

...
libgnutls.so.26 => ../lib/libgnutls.so.26
...
libgnutls.so.30 => ../lib/libgnutls.so.30
```

I think it needs libgnutls v3.6.9, but this library is not available for Centos 8 without compiling it from scratch. Any reccomendations?

Thanks for your help.

[ggarra13]

I think you have messed your symbolic links somehow. mrViewer ships with and uses libgnutls.so.26.22.6 (or the symlink libgnutls.so.26). This in turn requires libp11-kit.so.0 which is also included.

$ cd /path/to/mrviewer/bin
$ export LD_LIBRARY_PATH=../lib
$ ldd mrViewer | grep libgnu
libgnutls.so.26 => ../lib/libgnutls.so.26 (0x00007f60c9ff8000)
$ ldd mrViewer | grep libp11
libp11-kit.so.0 => ../lib/libp11-kit.so.0 (0x00007f5296e96000)

Try running mrViewer with the mrViewer.sh script which should set the LD_LIBRARY_PATH correctly, and make sure there are no additional libgnutls.so in the lib directory.

[Jedediah Smith]

Thanks for your reply!

Here is a more detailed breakdown of what I'm doing and what I'm seeing.

1. download mrViewer-v6.1.6-Linux-64.tar.gz
2. extract the tar
3. cd mrViewer-v6.1.6-Linux-64/usr/local/mrViewer-v6.1.6-Linux-64/bin/

$ ./mrViewer.sh
/path/to/mrviewer/bin/mrViewer: /path/to/mrviewer/lib/libp11-kit.so.0: no version information available (required by /lib64/libgnutls.so.30)
/path/to/mrviewer/bin/mrViewer: symbol lookup error: /lib64/libgnutls.so.30: undefined symbol: asn1_der_decoding2, version LIBTASN1_0_3
$ ldd mrViewer | grep libgnu
./mrViewer: ../lib/libp11-kit.so.0: no version information available (required by /lib64/libgnutls.so.30)
libgnutls.so.26 => ../lib/libgnutls.so.26 (0x00007f170d9dd000)
libgnutls.so.30 => /lib64/libgnutls.so.30 (0x00007f170833c000)

$ ldd mrViewer | grep libp11
./mrViewer: ../lib/libp11-kit.so.0: no version information available (required by /lib64/libgnutls.so.30)
libp11-kit.so.0 => ../lib/libp11-kit.so.0 (0x00007f5d5c6d5000)

It seems like somehow my system libgnutls.so.30 is being pulled into the library linking... :/

[ggarra13]

Ugh! That's really nasty. Try the following. Before running mrViewer.sh, do:

$ export LD_PRELOAD="/usr/lib64/libtasn1.so.6"
$ mrViewer.sh

If that works, you can add the preload env var to mrViewer.sh directly.

[ggarra13]

or:

$ export LD_PRELOAD="/lib64/libtasn1.so.6"
$ mrViewer.sh

if that's where libtasn1.so.6 is.

[Jedediah Smith]

I tried this but it doesn't seem to change the behavior :C

[ggarra13]

Okay, unset LD_PRELOAD. Now to be thorough can you do the following:

$ nm -D /lib64/libtasn1.so.6 | grep asn1_der_decoding
00000000000099b0 T asn1_der_decoding
00000000000089d0 T asn1_der_decoding2
00000000000099d0 T asn1_der_decoding_element
00000000000099f0 T asn1_der_decoding_startEnd

or wherever libtasn1.so.6 is. We need to make sure it contains asn1_der_decoding2.

If it does, remove libtasn1.so* from the path/to/mrviewer/lib directory and try again.

[ggarra13]

Also, in case it still does not work, run the following:

$ cd /path/to/mrviewer/bin
$ export LD_LIBRARY_PATH=../lib
$ strace mrViewer &> log.txt

And send the resulting log.txt as an attachment in your next post. That should get me debug why there's two libgnutls.so being loaded.

[Jedediah Smith]

Thanks for helping me troubleshoot this! I did as you suggested and removed the libtasn1.so* from the mrviewer lib directory. Unfortunately it does not seem to change the behavior.

I have attached the strace from a clean install with the following steps:
$ cd /path/to/mrviewer/bin
$ export LD_LIBRARY_PATH=../lib
$ strace ./mrViewer &> log.txt

Hope it helps!

[ggarra13]

OK. I found the tool I needed, as strace was kind of useless.
Install lddtree (from app-misc/pax-utils). Then do:

$ cd /path/to/mrviewer/bin
$ export LD_LIBRARY_PATH=../lib
$ lddtree ./mrViewer > tree.txt

and send me the file as an atachment.

[Jedediah Smith]

Thanks! I tried the one you compiled with ubuntu 20.04 LTS but I get a bunch of GLIBC errors like versionGLIBC_2.29' not found` - I'm assuming this means that the versions of GLIBC are different between the distributions :(

I tried out lddtree (very cool tool I wish I had known about this before! :D )

I've attached the output of lddtree. It looks like libgnutls.so.30 is being pulled in by libpango-1.0.so.0 then libglib-2.0.so.0.

Based on that info I downloaded glib2-2.56.1-7.el7.x86_64.rpm, extracted libglib-2.0.so* and added it to the /path/to/mrviewer/libs directory, and it opens and seems to work as expected.

[ggarra13]

Based on that info I downloaded glib2-2.56.1-7.el7.x86_64.rpm, extracted libglib-2.0.so* and added it to the /path/to/mrviewer/libs directory, and it opens and seems to work as expected.

Great! I am glad you made it work. I'll have to add libglib-2.0.so to the distribution to work around Red Hat's crazy implementation of their own. That should make it into v6.1.7.

[Jedediah Smith]

Sounds good. Thanks a lot for your help and support!