Package: python3-pysmi
Version: 0.3.4-3
Severity: important
Hi,
I've just spotted something a little weird while working on a customer
package that ships a number of MIBs that are processed via pysmi at
build time:
- the package builds fine in a trixie devel schroot;
- the package fails to build in a clean trixie cowbuilder chroot.
At first I suspected some build-depends might be missing (it declares
debhelper and python3-pysmi only), but the error is in importlib, which
is shipped alongside Python:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/pysmi/searcher/pyfile.py", line 15,
in <module>
SOURCE_SUFFIXES = importlib.machinery.SOURCE_SUFFIXES
^^^^^^^^^^^^^^^^^^^
AttributeError: module 'importlib' has no attribute 'machinery'
During handling of the above exception, another exception occurred:
I've tried replicating this with a bare trixie chroot, and I'm getting
similar results with either trixie or bookworm after setting them up
this way:
suite=bookworm # or trixie
sudo debootstrap $suite $suite
sudo chroot $suite
apt-get install -y python3
Non-interactively:
root@tokyo:/# python3 -c 'import importlib; print(importlib.machinery)'
Traceback (most recent call last):
File "<string>", line 1, in <module>
AttributeError: module 'importlib' has no attribute 'machinery'
Interactively:
root@tokyo:/# python3
Python 3.11.2 (main, Apr 28 2025, 14:11:48) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import importlib; print(importlib.machinery)
<module 'importlib.machinery' (frozen)>
Using dir() shows slightly different results:
root@tokyo:/# python3 -c 'import importlib; print(dir(importlib))'
['_RELOADING', '__all__', '__builtins__', '__cached__', '__doc__',
'__file__', '__import__', '__loader__', '__name__', '__package__', '__path__',
'__spec__', '_bootstrap', '_bootstrap_external', '_imp', '_pack_uint32',
'_unpack_uint32', 'import_module', 'invalidate_caches', 'reload', 'sys']
root@tokyo:/# python3
Python 3.13.5 (main, Jun 25 2025, 18:55:22) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import importlib; print(dir(importlib))
['_RELOADING', '__all__', '__builtins__', '__cached__', '__doc__',
'__file__', '__import__', '__loader__', '__name__', '__package__', '__path__',
'__spec__', '_abc', '_bootstrap', '_bootstrap_external', '_imp',
'_pack_uint32', '_unpack_uint32', 'import_module', 'invalidate_caches',
'machinery', 'reload', 'sys', 'util']
Extra entries: _abc, machinery, and util.
As mentioned in introduction, the interactive part is not necessarily
the critical bit, as that might work within devel schroots (I'm not sure
what the changes are, different set of packages, environment variables,
something else…).
Anyway, regardless of the exact details, since pysmi is in the middle of
some autodetection, it would probably be best not to rely on the exact
details of importlib's bootstrap (I only glanced at its internals)…
There are four occurrences of the following, with slight variations:
try:
import importlib
try:
SOURCE_SUFFIXES = importlib.machinery.SOURCE_SUFFIXES
BYTECODE_SUFFIXES = importlib.machinery.BYTECODE_SUFFIXES
except Exception:
raise ImportError()
(found in pysmi/searcher/pyfile.py, pysmi/searcher/pypackage.py,
pysmi/writer/pyfile.py, and pysmi/borrower/pyfile.py)
It seems something based on the following instead could work more
reliably:
from importlib.machinery import SOURCE_SUFFIXES, BYTECODE_SUFFIXES
Ditto for the util bit (based on the dir() output above), only found in
pysmi/searcher/pypackage.py):
from importlib.util import MAGIC_NUMBER
since the same behaviour can be observed with the “bare” importlib
import:
root@tokyo:/# python3 -c 'import importlib; print(importlib.util)'
Traceback (most recent call last):
File "<string>", line 1, in <module>
import importlib; print(importlib.util)
^^^^^^^^^^^^^^
AttributeError: module 'importlib' has no attribute 'util'
root@tokyo:/# python3
Python 3.13.5 (main, Jun 25 2025, 18:55:22) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import importlib; print(importlib.util)
<module 'importlib.util' (frozen)>
Thanks for considering, and sorry for not debugging this all the way.
Cheers,
--
Cyril Brulebois -- Debian Consultant @ DEBAMAX -- https://debamax.com/
