Cast bun.FD.uv({}) makes closing impossible! The supplier o

Error message

Cast bun.FD.uv({}) makes closing impossible!

The supplier of fd FD should call 'FD.makeLibUVOwned', probably where open() was called.

What it means

Error "Cast bun.FD.uv({}) makes closing impossible! The supplier of fd FD should call 'FD.makeLibUVOwned', probably where open() was called." thrown in oven-sh/bun.

Source

Thrown at src/bun_core/util.rs:1008

                if Some(self) == fd::WINDOWS_CACHED_STDIN.get().copied() {
                    return 0;
                }
                if Some(self) == fd::WINDOWS_CACHED_STDOUT.get().copied() {
                    return 1;
                }
                if Some(self) == fd::WINDOWS_CACHED_STDERR.get().copied() {
                    return 2;
                }
                if fd::is_stdio_handle(fd::STD_INPUT_HANDLE, handle) {
                    return 0;
                }
                if fd::is_stdio_handle(fd::STD_OUTPUT_HANDLE, handle) {
                    return 1;
                }
                if fd::is_stdio_handle(fd::STD_ERROR_HANDLE, handle) {
                    return 2;
                }
                panic!(
                    "Cast bun.FD.uv({}) makes closing impossible!\n\n\
                     The supplier of fd FD should call 'FD.makeLibUVOwned',\n\
                     probably where open() was called.",
                    self,
                );
            }
        }
    }

    #[cfg(not(windows))]
    #[inline]
    pub const fn stdin() -> Fd {
        Fd(0)
    }
    #[cfg(not(windows))]
    #[inline]
    pub const fn stdout() -> Fd {
        Fd(1)

View on GitHub (pinned to 8c5296ac45)

When it happens

Trigger: Thrown at src/bun_core/util.rs:1008 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of oven-sh/bun@8c5296ac45 (2026-08-16). Data as JSON: /api/errors/3fe5d748502ed76e. Report an issue: GitHub.