Nextjs

Dollar-prefixed action inputs can reach React Flight decoding. Reproduce decoding locally, compare error digests, and avoid mistaking a parser signal for RCE.

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.

A Next.js 15 dev server returned 500 with "TypeError: Cannot read properties of undefined (reading 'length')" from a generated page.js. The code at fault was webpack's installChunk: a second Next process, here a coding agent's build and dev server, was writing into the same .next directory.