NoirLogger

Frame delay. sleep (fiber-aware) rather than LibC.usleep, which would block the whole scheduler now that the spinner is a fiber.

IO::Error#os_error is Errno | WinError | WasiError | Nil — on Windows a broken pipe surfaces as a WinError, not an Errno, so comparing straight against Errno::EPIPE silently never matches there. WinError#to_errno normalizes it (ERROR_BROKEN_PIPE / ERROR_NO_DATA both map to Errno::EPIPE). Noir doesn't ship a WASI build, so WasiError — whose own #to_errno doesn't even compile on every native target (it references an Errno member some platforms' bindings omit) — is intentionally left out of this check.

Block form for messages that cost something to build. The message overload takes an already-built String, so debug "...#{expensive}" pays for the interpolation on every call and then throws it away with debug off; debug { "...#{expensive}" } doesn't build it at all.