skip PythonProcess preimport on macOS#37506
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utkarshgill wants to merge 1 commit intocommaai:masterfrom
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skip PythonProcess preimport on macOS#37506utkarshgill wants to merge 1 commit intocommaai:masterfrom
utkarshgill wants to merge 1 commit intocommaai:masterfrom
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…rk crash PythonProcess.prepare() preimports modules like selfdrive.ui.ui, which loads raylib and initializes CoreFoundation. When the manager subsequently forks child processes, macOS detects CoreFoundation was active pre-fork and crashes every child with "You MUST exec()". The process exits in ~1.5s. Skip preimporting on Darwin. Modules are still imported normally when each child process starts.
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Fixes #37504
manager.pymodule-level imports create OS threads (sentry) beforeunblock_stdout()callsos.forkpty(). The forkpty child -- which never exec's -- then runsprepare(), whichpreimports
selfdrive.ui.ui→ raylib → CoreFoundation. macOS kills the child (SIGSEGV)because CoreFoundation was initialized inside a fork-without-exec of a multi-threaded process.
This skips preimport on Darwin. Modules are still imported normally when each child starts
via multiprocessing spawn (fork+exec → fresh interpreter). Only startup speed is affected
on macOS, no functional change on Linux.
OBJC_DISABLE_INITIALIZE_FORK_SAFETYdoesn't work on macOS 14+. A full fix would bereworking
unblock_stdout()to avoid forkpty on macOS, but that's a bigger change.