{
  "id": 18666384,
  "title": "Your Agent's Command Printed Nothing for 2 Minutes. stdout Wasn't a Terminal",
  "url": "https://urgent.news/2026/11/07/your-agents-command-printed-nothing-for-2-minutes-stdout-wasnt-a",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-11-07T08:02:16.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/gabrielanhaia/your-agents-command-printed-nothing-for-2-minutes-stdout-wasnt-a-terminal-1baj"
  },
  "original_language": "en",
  "account": "Claude Code's Bash tool executes commands in separate processes and streams their output to a file. When a command exceeds its two-minute timeout, it is moved to the background, and Claude Code returns a message with the task ID and the path of the output file. However, for block-buffered commands, the file may contain only the data that has been flushed so far, which could be empty. This issue arises because the check for a terminal (isatty()) fails under an agent, causing the command to use block buffering instead of line buffering. As a result, lines are not displayed in real-time, but instead accumulate in memory until the buffer is full, the program calls fflush, or the process exits normally. To resolve this issue, Python developers can run their scripts with the -u flag or set PYTHONUNBUFFERED to 1, forcing the buffer to flush after each print statement. Additionally, Claude Code's settings can be customized to include the env key, which sets variables for every session and its subprocesses.",
  "summary": "Book: AI That Acts The series: AI in TypeScript — 5 books, from your first LLM call to agents in production — all five here My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub Command did not complete within its 120s timeout and was moved to the background . That is what Claude Code hands back after two minutes, the…",
  "key_points": [
    "Claude Code's Bash tool streams command output to a file",
    "Two-minute timeout moves command to background",
    "Block-buffered commands may have empty output file"
  ],
  "editors_take": "The failure to recognize a terminal environment forces block buffering on commands, which hides real-time progress from agents and requires manual configuration of environment variables to ensure visibility.",
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}