try/except usage of importlib.metadata/importlib_metadata does not work on 3.7 or lower

Hello

I used nuitka 0.7.7 for a long time without problems. After upgrade to 1.0.3 I started to receive an error (importlib_metadata.PackageNotFoundError) in my project that previously worked correct.

importlib_metadata.PackageNotFoundError: No package metadata was found for prettytable

Nuitka version:

1.0.3
Commercial: None
Python: 3.6.8 (default, Aug 13 2020, 07:46:32)
Flavor: Fedora Python
Executable: /home/rlm_dev/ushd/sds_discovery/bin/python
OS: Linux
Arch: x86_64
Distribution: Rhel (based on Fedora) 7.9

Pip list:

Package            Version
------------------ ---------
attrs              21.4.0
boto3              1.23.10
botocore           1.26.10
certifi            2022.6.15
charset-normalizer 2.0.12
idna               3.3
importlib-metadata 4.8.3
jmespath           0.10.0
Nuitka             1.0.3
orderedset         2.0.3
pip                21.3.1
prettytable        2.5.0
psycopg2-binary    2.9.3
python-dateutil    2.8.2
requests           2.27.1
requests-aws       0.1.8
rgwadmin           2.3.1
s3transfer         0.5.2
setuptools         39.2.0
six                1.16.0
typing_extensions  4.1.1
urllib3            1.26.9
wcwidth            0.2.5
zipp               3.6.0

I tested some versions of nuitka and found out that last worked version is 0.8.4 and problem started from 0.9. Test program test.py:

import prettytable

def main():
    print("hello world")
    return

 if __name__ == '__main__':
    main()

Nuitka 1.0.3:

(sds_discovery) [[rlm_dev@tkles](mailto:rlm_dev@tkles) /home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering]$ python -m nuitka --standalone test.py
Nuitka-Options:INFO: Used command line options: --standalone test.py
Nuitka:INFO: Starting Python compilation with Nuitka '1.0.3' on Python '3.6' commercial grade 'not installed'.
Nuitka-Plugins:INFO: multiprocessing: Injecting pre-module load code for module 'multiprocessing':
Nuitka-Plugins:INFO: multiprocessing:     Monkey patching "multiprocessing" load environment.
Nuitka-Plugins:INFO: multiprocessing: Injecting post-module load code for module 'multiprocessing':
Nuitka-Plugins:INFO: multiprocessing:     Monkey patching "multiprocessing" for compiled methods.
Nuitka:INFO: Completed Python level compilation and optimization.
Nuitka:INFO: Generating source code for C backend compiler.
Nuitka:INFO: Running data composer tool for optimal constant value handling.
Nuitka:INFO: Running C compilation via Scons.
Nuitka-Scons:INFO: The provided gcc is too old, switching to its g++ instead.
Nuitka-Scons:INFO: Backend C compiler: g++ (g++).
Nuitka-Scons:INFO: Backend linking program with 22 files (no progress information available).
Nuitka-Scons:INFO: Compiled 22 C files using ccache.
Nuitka-Scons:INFO: Cached C files (using ccache) with result 'cache hit': 6
Nuitka-Scons:INFO: Cached C files (using ccache) with result 'cache miss': 15
Nuitka:INFO: Keeping build directory 'test.build'.
Nuitka:INFO: Successfully created 'test.dist/test'.

Traceback (most recent call last):
 File "/home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering/test.dist/test.py", line 1, in <module>
 File "/home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering/test.dist/prettytable/__init__.py", line 52, in <module prettytable>
 File "/home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering/test.dist/importlib_metadata/__init__.py", line 990, in version
 File "/home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering/test.dist/importlib_metadata/__init__.py", line 963, in distribution
 File "/home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering/test.dist/importlib_metadata/__init__.py", line 542, in from_name
importlib_metadata.PackageNotFoundError: No package metadata was found for prettytable

Nuitka 0.8.4:

INFO:  Start nuitka
Nuitka-Options:INFO: Used command line options: --standalone sds/sds_discovering/scripts/sds_discovery.py
Nuitka:INFO: Starting Python compilation with Nuitka '0.8.4' on Python '3.6' commercial None.
Nuitka-Plugins:INFO: anti-bloat: Handling module 'certifi.core' with 1 change(s) for: avoid using importlib.resources without need.
Nuitka-Plugins:INFO: multiprocessing: Injecting pre-module load code for module 'multiprocessing':
Nuitka-Plugins:INFO: multiprocessing:     Monkey patching "multiprocessing" load environment.
Nuitka-Plugins:INFO: multiprocessing: Injecting post-module load code for module 'multiprocessing':
Nuitka-Plugins:INFO: multiprocessing:     Monkey patching "multiprocessing" for compiled methods.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'urllib3' added 'urllib3,urllib3._collections,urllib3.connection,urllib3.connectionpool,urllib3.contrib,urllib3.contrib.appengine,urllib3.exceptions,urllib3.fields,urllib3.filepost,urllib3.packages,urllib3.packages.six,urllib3.poolmanager,urllib3.request,urllib3.response,urllib3.util,urllib3.util.connection,urllib3.util.queue,urllib3.util.request,urllib3.util.response,urllib3.util.retry,urllib3.util.ssl_,urllib3.util.timeout,urllib3.util.url,urllib3.util.wait,urllib.error,urllib.parse,urllib.request,urllib.response'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'boto3' added 'boto3.ec2,boto3.ec2.createtags,boto3.ec2.deletetags,boto3.dynamodb,boto3.s3,boto3.s3.inject,boto3.s3.transfer'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'zipfile' added 'py_compile'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'urllib.request' added 'http.client,http.cookiejar'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'socket' added '_socket'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'shelve' added 'dbm.dumb'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'pathlib' added 'ntpath,posixpath'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'ctypes' added '_ctypes'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module '_asyncio' added 'asyncio'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'locale' added '_bootlocale'.
Nuitka-Plugins:INFO: implicit-imports: Implicit dependencies of module 'encodings' added 'encodings.idna,encodings.base64_codec,encodings.hex_codec,encodings.rot_13'.
Nuitka:INFO: Completed Python level compilation and optimization.
Nuitka:INFO: Generating source code for C backend compiler.
Nuitka:INFO: Running data composer tool for optimal constant value handling.
Nuitka:INFO: Running C compilation via Scons.
Nuitka-Scons:INFO: The provided gcc is too old, switching to its g++ instead.
Nuitka-Scons:INFO: Backend C compiler: g++ (g++).
Nuitka-Scons:INFO: Backend linking program (no progress information available).
Nuitka-Scons:INFO: Compiled 273 C files using ccache.
Nuitka-Scons:INFO: Cached C files (using ccache) with result 'cache hit': 272
Nuitka-Plugins:INFO: data-files: Included 16 data files due to package data directory 'data' for 'boto3'.
Nuitka-Plugins:INFO: data-files: Included data file 'botocore/cacert.pem' due to package data for 'botocore'.
Nuitka-Plugins:INFO: data-files: Included 906 data files due to package data directory 'data' for 'botocore'.
Nuitka-Plugins:INFO: data-files: Included data file 'certifi/cacert.pem' due to package data for 'certifi'.
Nuitka:INFO: Keeping build directory 'sds_discovery.build'.
Nuitka:INFO: Successfully created 'sds_discovery.dist/sds_discovery'.

(sds_discovery) [[rlm_dev@tkles](mailto:rlm_dev@tkles) /home/rlm_dev/ushd/sds_discovery/sds/sds/sds_discovering]$ ./test.dist/test
hello world

In addition I tried some options for solving the problem. Without success.

python -m nuitka --standalone --include-package=prettytable test.py
python -m nuitka --standalone --follow-stdlib test.py
python -m nuitka --standalone --full-compat test.py
python -m nuitka --standalone --disable-plugin=anti-bloat test.py

Could you help me to solve this problem?

Thanks.

[kayhayen]

It seems, this pattern is not working for static optimization in Nuitka:

try:
    # Python 3.8+
    import importlib.metadata as importlib_metadata
except ImportError:
    # <Python 3.7 and lower
    import importlib_metadata

__version__ = importlib_metadata.version(__name__)
```

I think for 3.8+ the exception handler goes away, and the hard import is being done and compile time resolves it to the version value. When the import is not available at compile time, I think so far it is not statically converted to an `ImportError` not is that exception handler optimized away. I will have to check it out.

[kayhayen]

Part of the 1.2 release that was made a while ago.