[BUG] fastfetch failed to retrieve command output

[dwlfrth]

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General description of bug:

• What happened: Command output is not displayed
• What should happen: Command output should be displayed
• Fastfetch version used: fastfetch 2.30.1 (aarch64)
• Did it work in an older version: N/A
• Where did you get the binary: Homebrew
• Does this issue still occur in the latest dev build? N/A

Often helpful information:

Screenshot:

N/A

The content of the configuration file you use (if any):

{
  "type": "command",
  "text": "/usr/bin/ssh-agent",
}

Output of fastfetch -c ci.jsonc --format json:

N/A

Output of fastfetch --list-features:

threads
vulkan
imagemagick7
chafa
zlib
sqlite3

[dwlfrth]

Note: The command is being executed successfully...

[CarterLi]

Confirmed that it works in Linux but not macOS

[CarterLi]

Confirmed that it works in FreeBSD & NetBSD too despite they all share the same code.

I assume it's a macOS kernel bug.

[CarterLi]

Reverted the fix commit https://github.com/fastfetch-cli/fastfetch/commit/e9ab67b380734d5c9527376b0b5e38b90bf37b97

The fix, which relies SIGCHILD to interupt poll(2) calls, causes issues as now Command module can be executed in parallel. This issue happens only in macOS & only happens if you spawn a process which forks itself as a daemon process. One should never do this in fastfetch as the daemon processes never exit.