{"record":{"id":"25523b2264b8af3d","repo":"ElectronNET/Electron.NET","slug":"unable-to-find-process-with-id-this-pid","errorCode":null,"errorMessage":"Unable to find process with ID {this.pid}","messagePattern":"Unable to find process with ID (.+?)","errorType":"exception","errorClass":"ArgumentException","httpStatus":null,"severity":"error","filePath":"src/ElectronNET.API/Runtime/Services/ElectronProcess/ElectronProcessPassive.cs","lineNumber":31,"sourceCode":"    internal class ElectronProcessPassive : ElectronProcessBase\n    {\n        private readonly int pid;\n        private Process process;\n\n        /// <summary>Initializes a new instance of the <see cref=\"ElectronProcessPassive\"/> class.</summary>\n        /// <param name=\"pid\"></param>\n        public ElectronProcessPassive(int pid)\n        {\n            this.pid = pid;\n        }\n\n        protected override Task StartCore()\n        {\n            this.process = Process.GetProcessById(this.pid);\n\n            if (this.process == null)\n            {\n                throw new ArgumentException($\"Unable to find process with ID {this.pid}\");\n            }\n\n            this.process.Exited += this.Process_Exited1;\n\n            Task.Run(() => this.TransitionState(LifetimeState.Ready));\n\n            return Task.CompletedTask;\n        }\n\n        private void Process_Exited1(object sender, EventArgs e)\n        {\n            this.TransitionState(LifetimeState.Stopped);\n        }\n\n        protected override Task StopCore()\n        {\n            // Not sure about this:\n            ////this.process.Kill(true);","sourceCodeStart":13,"sourceCodeEnd":49,"githubUrl":"https://github.com/ElectronNET/Electron.NET/blob/87cc6f98b6a9c5968d7846c0e775ea713bd0d7b2/src/ElectronNET.API/Runtime/Services/ElectronProcess/ElectronProcessPassive.cs#L13-L49","documentation":"ElectronProcessPassive.StartCore attaches to an already-running Electron process by PID using Process.GetProcessById. .NET's GetProcessById throws ArgumentException when no process with that ID exists; the subsequent null check with this custom message is the library's guard for a missing process.","triggerScenarios":"Starting the passive Electron process lifecycle with a PID that has already exited, a PID from a different OS namespace (e.g. container/host mismatch), or a stale/incorrect PID value.","commonSituations":"Attaching to an Electron host that crashed or was closed before the .NET side started; passing a PID captured long before use; WSL/container PID isolation hiding the host process.","solutions":["Verify the target process with the given PID is actually running before starting (Process.GetProcesses / ps)","Re-launch the Electron host and use its fresh PID","Check for PID namespace issues when running in containers/WSL","Confirm the PID is not from a previous, terminated run"],"exampleFix":"// before\nvar proc = Process.GetProcessById(pid); // ArgumentException if gone\n// after\nif (!Process.GetProcesses().Any(p => p.Id == pid))\n    throw new InvalidOperationException($\"Process {pid} is not running\");\nvar proc = Process.GetProcessById(pid);","handlingStrategy":"validation","validationCode":"if (!Process.GetProcesses().Any(p => p.Id == pid))\n    throw new InvalidOperationException($\"Electron host process {pid} is not running\");","typeGuard":"bool ProcessExists(int pid) => Process.GetProcesses().Any(p => p.Id == pid);","tryCatchPattern":"try\n{\n    await electronProcess.StartAsync();\n}\ncatch (ArgumentException ex)\n{\n    logger.LogWarning(ex, \"Host process {Pid} no longer exists — relaunching\", pid);\n    await relaunchHostAsync();\n}","preventionTips":["Use the PID immediately after obtaining it; don't cache across restarts","Handle host crash events and re-launch rather than reusing stale PIDs","Beware container/WSL PID isolation when attaching across boundaries"],"tags":["process","pid","lifecycle"],"backgroundTag":"entity-not-found","analyzedSha":"87cc6f98b6a9c5968d7846c0e775ea713bd0d7b2","analyzedAt":"2026-09-14T03:09:47.608Z","contentChangedAt":"2026-09-14T03:09:47.608Z","schemaVersion":2},"datasetVersion":"2026-09-16T04:17:20.429Z"}