Passenger 6.0.27 – spawn failure with errno=24, very high number of open FDs

We’re running Passenger on a shared hosting environment, where users run their own applications via Passenger. On Passenger 6.0.27 we’re seeing cases where an application fails to start. From passenger.log: ``` [ E 2025-12-14 12:58:08.0616 58412/Tjw3 age/Cor/App/Implementation.cpp:218 ]: Could not spawn process for application <REDACTED_APP_PATH>: An operating system error occurred while preparing to spawn an application process: Error looking up OS group account 1000: Too many open files (errno=24) ``` At the same time, PassengerAgent ends up with a very large number of open file descriptors (around 80k+). System limits are high (openfiles 3771288), so it doesn’t look like a ulimit problem. On Passenger 6.0.22 this setup was working fine: PassengerAgent typically had around 200 open files, not tens of thousands. After attaching truss to PassengerAgent, the process crashed, and after restart the problem temporarily disappeared.