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A background agent build could not find Dockerfile despite workdir being set. Bind paths inside the command and verify cwd in the same execution mode.

ISDOC is the Czech national e-invoicing format. Here is how to embed it in a PDF/A-3, how to check the result, and where it falls short of the VAT Act: a summary tax document needs a date for each supply, and ISDOC 6.0.2 has one per document.

An invoice number with an apostrophe broke a duplicate check. urllib.parse.quote() percent-encoded the filter, the API decoded it before parsing, the malformed query got a 400, the finder returned None, and the caller pushed the invoice again.

An ERP API can answer a PUT with a 500 after it has saved the invoice. A client that retries gets a 200 and reports success with two invoices on the books. Idempotency keys and verify-by-GET did not help, because they ran outside the retry loop.

A branch built with a coding agent passed lint, 1,572 Python tests and 418 GUI tests. A review by a different model, split into a Standards subagent and a Spec subagent, still found two ways to write the same record twice. The Spec reviewer got there by checking what the commit messages promised against the code.

A coding agent found a bug mid-refactor and parked it as a known issue with `@unittest.expectedFailure`. Two `git log -S` runs showed nobody had ever decided it, so it was fixed the same night. The obvious `.extend()` fix would have broken an alias. Includes the skill that does the dating.

An upload classifier sent a language model the first page of each PDF. The helper indexed a dataclass like a list, the TypeError was caught and turned into an empty string, and for seven weeks the model classified every PDF by filename alone, with a confidence score attached.

Inside its sandbox, a coding agent hit "Could not find a working container runtime strategy" and "listen EPERM: operation not permitted 0.0.0.0:8080", filed every failure under "environment" and committed. On the host, three tests failed, and the skipped `next build` stayed broken for two months.

A coding agent ran pnpm test and got ERR_PNPM_ABORTED_REMOVE_MODULES_DIR_NO_TTY from pnpm 11, in a repo pinned to pnpm 10. The agent's runtime ships its own pnpm and turns off the packageManager check. Following the CI=true hint reinstalled node_modules, filled the disk, edited pnpm-workspace.yaml and lost a native Next.js binary.

In a git worktree whose node_modules was a symlink to the main checkout, tsc reported TS2724 "has no exported member" for a function the worktree exported. pnpm links workspace packages with relative symlinks, and those resolve inside the main checkout, so typecheck and tests ran against the old source of every workspace package.