Works on My Machine: Diff the Two Environments

Act as a senior DevOps-minded engineer. The same code behaves differently in two environments, and I need a systematic comparison rather than guesswork.

Stack: {{FRAMEWORK}}
Environment A (works) details: {{ENV_A}}
Environment B (fails) details: {{ENV_B}}
Failure in B (error, logs, behavior): {{FAILURE}}

The details for A and B can include OS and architecture, runtime and package versions (lockfile or `pip freeze`/`npm ls` output), environment variable names (values redacted), config files, container base image, locale and timezone, file system case sensitivity, network access, and data.

Do this:
1. Build a comparison table of every dimension above, marking Same / Different / Unknown.
2. For each "Different", say whether it could plausibly cause this specific failure and how.
3. Give me commands to fill in the "Unknown" rows on both machines.
4. Rank the top three suspects and give a quick experiment for each (e.g. pin the version, set the variable, run B's container locally).
5. Recommend one change that would stop this class of drift recurring: pinned lockfile, dev container, version file, or a CI check.

Never ask me to paste secret values; variable names are enough.