Bug: inspect.getframeinfo fails in blingfire/__init__.py when imported within timeit or certain contexts

[speedyk-005]

Description

When importing blingfire (v0.1.8 or v0.2.1) within certain runtime contexts, specifically:

• Inside timeit.repeat() lambda functions
• Inside pydantic validate wrappers

The import fails with:

...
File "/home/spdk/projects/chunklet-py/.venv/lib/python3.12/site-packages/blingfire/__init__.py", line 8, in <module>
    filename = inspect.getframeinfo(inspect.currentframe()).filename
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/spdk/.local/share/uv/python/cpython-3.12.13-linux-x86_64-gnu/lib/python3.12/inspect.py", line 1718, in getframeinfo
    lines, lnum = findsource(frame)
                  ^^^^^^^^^^^^^^^^^
  File "/home/spdk/.local/share/uv/python/cpython-3.12.13-linux-x86_64-gnu/lib/python3.12/inspect.py", line 1090, in findsource
    module = getmodule(object, file)
             ^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/spdk/.local/share/uv/python/cpython-3.12.13-linux-x86_64-gnu/lib/python3.12/inspect.py", line 1013, in getmodule
    f = getabsfile(module)
        ^^^^^^^^^^^^^^^^^^
  File "/home/spdk/.local/share/uv/python/cpython-3.12.13-linux-x86_64-gnu/lib/python3.12/inspect.py", line 982, in getabsfile
    _filename = getsourcefile(object) or getfile(object)
                ^^^^^^^^^^^^^^^^^^^^^
  File "/home/spdk/.local/share/uv/python/cpython-3.12.13-linux-x86_64-gnu/lib/python3.12/inspect.py", line 958, in getsourcefile
    if any(filename.endswith(s) for s in all_bytecode_suffixes):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/spdk/.local/share/uv/python/cpython-3.12.13-linux-x86_64-gnu/lib/python3.12/inspect.py", line 958, in <genexpr>
    if any(filename.endswith(s) for s in all_bytecode_suffixes):
           ^^^^^^^^^^^^^^^^^
AttributeError: 'function' object has no attribute 'endswith'

Steps to Reproduce

import timeit
from blingfire import text_to_sentences

text = "Hello world. How are you?" * 10

# This will fail
t = min(timeit.repeat(lambda: text_to_sentences(text), number=10, repeat=5)) * 1000

Root Cause

In blingfire/__init__.py line 8:

filename = inspect.getframeinfo(inspect.currentframe()).filename

The issue is in Python's inspect.getsourcefile() which tries to get the source file of a function object, but in certain contexts (timeit, pydantic wrappers) the object passed is a function rather than a module, causing endswith to fail.

Expected Fix

Replace the inspect-based filename detection with a more robust approach:

# Option 1: Use __file__ directly
from blingfire import __file__ as filename

# Option 2: Catch the AttributeError and fallback
try:
    filename = inspect.getsourcefile(blingfire)
except AttributeError:
    filename = blingfire.__file__

Environment

• Python 3.12
• blingfire 0.1.8 / 0.2.1
• Linux x86_64

Additional Context

This bug does NOT occur when calling text_to_sentences() directly outside of timeit. It only fails in specific runtime introspection contexts.