libstdc++.so.6: version `GLIBCXX_3.4.30' not found

I'm encountering an issue where:

1. A Conda package is built against libc 3.4.30 (in this case, python-casacore).
2. Conda ships with libc 3.4.30.
3. Running `ldd libcasa_casa.so` shows that casa is correctly linked to the Conda version of libc.
4. If I enter the Julia-managed conda (`~/.julia/3/bin/python`) and `import casacore.tables` it works fine.

BUT, when I `pyimport("casacore.tables")` I get the following error:

ImportError("/home/torrance/julia-1.7.3/bin/../lib/julia/libstdc++.so.6: version `GLIBCXX_3.4.30' not found (required by /home/torrance/.julia/conda/3/lib/python3.9/site-packages/casacore/tables/../../../../libcasa_tables.so.7)")

It looks like to me that when run in the context of Julia, the `pyimport` statement wants to preferentially link against the Julia supplied libc, and not the Conda supplied libc. Moreover, the Julia supplied libc is at version 3.4.29.

Is this choice to link against the Julia libc a deliberate choice? If so, how to we mitigate this kind of issue happening each time Conda and Julia libc versions aren't aligned?

The report names no source files or tests; begin by reproducing the `pyimport("casacore.tables")` failure and comparing it with the working `import casacore.tables` in the Julia-managed Conda environment. Trace how PyCall loads Julia's bundled libstdc++ versus Conda's library, then define completion as an explained and verified mitigation for the GLIBCXX version mismatch.

Vom Indexierungsmodell aus dem Issue-Text verfasst.