package_version() parses every installed package's metadata, slowing sentry_sdk.init() #8190

How do you use Sentry?

Sentry Saas (sentry.io)

Version

2.73.0

Steps to Reproduce

Steps to Reproduce

In an environment with a few hundred packages, with Flask installed:

import time
import flask
import sentry_sdk
from sentry_sdk.integrations.flask import FlaskIntegration

t = time.perf_counter()
sentry_sdk.init(
    dsn="https://abc@o1.ingest.sentry.io/1",
    integrations=[FlaskIntegration()],
    auto_enabling_integrations=False,
)
print(f"{(time.perf_counter() - t) * 1000:.0f} ms")

Background

Flask deprecated __version__ and #2316 suggested importlib.metadata.version. #2338 fixed the deprecation using _get_installed_modules() instead. #6769 / #6865 addressed the same scan for MCP when mcp isn't installed.

Suggested fix

Have package_version call importlib.metadata.version(package), keeping the existing path for Python < 3.8 and returning None on PackageNotFoundError. ModulesIntegration would still build the full list on the first error event. Happy to open a PR if this approach works for you.

Expected Result

Checking Flask's minimum version costs about as much as looking up one package.

Actual Result

FlaskIntegration.setup_once calls package_version("flask"), which parses the metadata of every installed package just to read one version. importlib.metadata.version("flask"), as suggested in #2316, reads only Flask's.

With ~250 packages: package_version("flask") takes 106 ms, and importlib.metadata.version("flask") takes 5 ms (-95%).