#3852 docs: explain remote debugging for targets reading stdin Pull request opened by henricop Description Targets consume Singer messages on stdin, which conflicts with an interactive PDB session. Add a developer-guide section using

remote-pdb

through

PYTHONBREAKPOINT

, a loopback socket, and a temporary

max_parallelism

override for sequential sink draining. Explain installing the debugger in the target's environment, reinstalling the Meltano plugin after adding a dependency (including editable installs), redirecting stdin, connecting and reconnecting, and removing the debugging settings afterward. Document the unauthenticated socket and trusted-host boundary. Validation: •

nox -s docs

passed with its default `-W`; the final rebuild had no warnings. • Ruff 0.16.6 Markdown formatting, mdformat 1.0.0, codespell 2.4.3 and whitespace checks passed for the changed document. • Executed the documented parallelism property in a real SDK target on Python 3.15: two Singer streams and a checkpoint went through stdin, two loopback debugger connections inspected and continued the records, both batches ran in the main thread, and the checkpoint reached stdout unchanged. Only the developer guide changes. The contributor personally reviewed and understood the initial patch and the final review follow-up before each was published. Checklist • I have read the contribution guide. • The contributor has personally reviewed and understood the final diff, as required by the Agentic Coding guidelines. Was generative AI tooling used to co-author this PR? • Yes — Codex. Generated-by: Codex following the agentic coding guidelines. Related Issues • Closes #911. meltano/sdk