Unable to use matlab bindings when installed via conda on Ubuntu 20.04

[S-Dafarra]

I am trying to use the robotology one line install to use the iDynTree wrappers in Matlab when iDynTree has not been installed previously. However, I am having the following error:

Invalid MEX-file '--/robotology-matlab/mex/iDynTreeMEX.mexa64': /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.29' not found (required by --/robotology-matlab/mex/iDynTreeMEX.mexa64)

when attempting to use one function of the wrappers.

I have also checked the following

strings /lib/x86_64-linux-gnu/libstdc++.so.6 | grep LIBCXX
GLIBCXX_3.4
GLIBCXX_3.4.1
GLIBCXX_3.4.2
GLIBCXX_3.4.3
GLIBCXX_3.4.4
GLIBCXX_3.4.5
GLIBCXX_3.4.6
GLIBCXX_3.4.7
GLIBCXX_3.4.8
GLIBCXX_3.4.9
GLIBCXX_3.4.10
GLIBCXX_3.4.11
GLIBCXX_3.4.12
GLIBCXX_3.4.13
GLIBCXX_3.4.14
GLIBCXX_3.4.15
GLIBCXX_3.4.16
GLIBCXX_3.4.17
GLIBCXX_3.4.18
GLIBCXX_3.4.19
GLIBCXX_3.4.20
GLIBCXX_3.4.21
GLIBCXX_3.4.22
GLIBCXX_3.4.23
GLIBCXX_3.4.24
GLIBCXX_3.4.25
GLIBCXX_3.4.26
GLIBCXX_3.4.27
GLIBCXX_3.4.28
GLIBCXX_DEBUG_MESSAGE_LENGTH

and indeed GLIBCXX_3.4.29 is missing.

I do not have this error when installing the bindings from source.

[S-Dafarra]

I have tried to set export LD_PRELOAD=/lib/x86_64-linux-gnu/libstdc++.so.6 before launching matlab, but then I have the error

installation finished.
WARNING:
    You currently have a PYTHONPATH environment variable set. This may cause
    unexpected behavior when running the Python interpreter in Mambaforge.
    For best results, please verify that your PYTHONPATH only points to
    directories of packages that are compatible with the Python interpreter
    in Mambaforge: --/robotology-matlab
Installation of mambaforge completed
Installing robotology packages
Traceback (most recent call last):
  File "--/robotology-matlab/condabin/mamba", line 7, in <module>
    from mamba.mamba import main
  File "--/robotology-matlab/lib/python3.10/site-packages/mamba/mamba.py", line 49, in <module>
    import libmambapy as api
  File "--/robotology-matlab/lib/python3.10/site-packages/libmambapy/__init__.py", line 7, in <module>
    raise e
  File "--/robotology-matlab/lib/python3.10/site-packages/libmambapy/__init__.py", line 4, in <module>
    from libmambapy.bindings import *  # noqa: F401,F403
ImportError: /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.29' not found (required by --/robotology-matlab/lib/python3.10/site-packages/libmambapy/bindings.cpython-310-x86_64-linux-gnu.so)
Installation of robotology packages completed
Creating setup script in --/robotology_setup.m
Deleting mambaforge installer

[traversaro]

Sorry, I understood the problem was on 22.04, not 20.04 . Then the problem issue is robotology/robotology-superbuild#1159 . The real workaround is to set LD_PRELOAD=$CONDA_PREFIX/lib/libstdc++.so.6, but the problem is that if you are using the one-line install, the $CONDA_PREFIX does not exists. Depending on the MATLAB version that you are using, it is possible that the libstdc++.so.6 shipped with MATLAB itself is new enough, in that case a possible workaround is to undo the usual workaround of renaming /usr/local/MATLAB/R<RELEASENAME>/sys/os/glnxa64/libstdc++.so.6 to /usr/local/MATLAB/R<RELEASENAME>/sys/os/glnxa64/libstdc++.so.6.bak, so that the libstdc++.so.6 shipped by MATLAB is used, but this may work only if MATLAB is new enough.

[S-Dafarra]

Depending on the MATLAB version that you are using, it is possible that the libstdc++.so.6 shipped with MATLAB itself is new enough, in that case a possible workaround is to undo the usual workaround of renaming /usr/local/MATLAB/R<RELEASENAME>/sys/os/glnxa64/libstdc++.so.6 to /usr/local/MATLAB/R<RELEASENAME>/sys/os/glnxa64/libstdc++.so.6.bak, so that the libstdc++.so.6 shipped by MATLAB is used, but this may work only if MATLAB is new enough.

I tried it, but I had the same error. I have R2021b