Grails: Process hasn't generated any output for a long time

Numerous exceptions found in a user's log.
```
2020-12-10 10:13:14,076 [9459635] WARN - n.process.BaseOSProcessHandler - Process hasn't generated any output for a long time.
If it's a long-running mostly idle daemon process, consider overriding OSProcessHandler#readerOptions with 'BaseOutputReader.Options.forMostlySilentProcess()' to reduce CPU usage.
Command line: C:\Java\jdk1.8.0_265\bin\java.exe -XX:+TieredCompilation -XX:TieredStopAtLevel=1 -XX:CICompilerCount=3 -Dfile.encoding=windows-1252 -Ddisable.auto.recompile=true -Dgrails.reload.enabled=false -Djava.library.path=C:\apps\rtfs2\libs\dcm4che-5-22-3 -Xms1536M -Xmx2048M -XX:ThreadStackSize=32M -Djline.WindowsTerminal.directConsole=false -Dgrails.full.stacktrace=true -classpath W:\temp\classpath2032357136.jar org.grails.cli.GrailsCli run-app --plain-output
java.lang.Throwable: Process creation:
at com.intellij.execution.process.BaseOSProcessHandler.(BaseOSProcessHandler.java:32)
at com.intellij.execution.process.OSProcessHandler.(OSProcessHandler.java:49)
at com.intellij.execution.process.KillableProcessHandler.(KillableProcessHandler.java:37)
at com.intellij.execution.process.ColoredProcessHandler.(ColoredProcessHandler.java:24)
at com.intellij.execution.process.KillableColoredProcessHandler.(KillableColoredProcessHandler.java:29)
at com.intellij.execution.process.KillableColoredProcessHandler.(KillableColoredProcessHandler.java:22)
at org.jetbrains.plugins.grails.runner.impl.BaseGrailsCommandLineState.startProcess(BaseGrailsCommandLineState.kt:17)
at org.jetbrains.plugins.grails.runner.impl.GrailsCommandLineState.startProcess(GrailsCommandLineState.java:116)
at org.jetbrains.plugins.grails.runner.impl.GrailsCommandLineState.startProcess(GrailsCommandLineState.java:27)
at com.intellij.execution.configurations.CommandLineState.execute(CommandLineState.java:61)
at org.jetbrains.plugins.grails.runner.impl.GrailsRunAppCommandLineState.execute(GrailsRunAppCommandLineState.kt:20)
at com.intellij.debugger.DefaultDebugEnvironment.createExecutionResult(DefaultDebugEnvironment.java:81)
at com.intellij.debugger.engine.DebugProcessImpl.attachVirtualMachine(DebugProcessImpl.java:2109)
at com.intellij.debugger.impl.DebuggerSession.attach(DebuggerSession.java:437)
at com.intellij.debugger.impl.DebuggerSession.create(DebuggerSession.java:198)
at com.intellij.debugger.impl.DebuggerManagerImpl.attachVirtualMachine(DebuggerManagerImpl.java:184)
at com.intellij.debugger.impl.GenericDebuggerRunner.attachVirtualMachine(GenericDebuggerRunner.java:151)
at org.jetbrains.plugins.grails.runner.GrailsDebuggerRunner.createContentDescriptor(GrailsDebuggerRunner.kt:78)
at com.intellij.debugger.impl.GenericDebuggerRunner.doExecute(GenericDebuggerRunner.java:80)
at com.intellij.debugger.impl.GenericDebuggerRunner.lambda$execute$1(GenericDebuggerRunner.java:72)
at com.intellij.execution.ExecutionManager$startRunProfile$1.invoke(ExecutionManager.kt:65)
at com.intellij.execution.ExecutionManager$startRunProfile$1.invoke(ExecutionManager.kt:19)
at com.intellij.execution.impl.ExecutionManagerImpl$startRunProfile$1.invoke(ExecutionManagerImpl.kt:155)
at com.intellij.execution.impl.ExecutionManagerImpl$startRunProfile$1.invoke(ExecutionManagerImpl.kt:65)
at com.intellij.execution.impl.ExecutionManagerImpl$doStartRunProfile$startRunnable$1.run(ExecutionManagerImpl.kt:216)
at com.intellij.openapi.application.TransactionGuardImpl.runWithWritingAllowed(TransactionGuardImpl.java:216)
at com.intellij.openapi.application.TransactionGuardImpl.access$200(TransactionGuardImpl.java:24)
at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:199)
at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:822)
at com.intellij.openapi.application.impl.ApplicationImpl.lambda$invokeLater$4(ApplicationImpl.java:324)
at com.intellij.openapi.application.impl.FlushQueue.doRun(FlushQueue.java:85)
at com.intellij.openapi.application.impl.FlushQueue.runNextEvent(FlushQueue.java:134)
at com.intellij.openapi.application.impl.FlushQueue.flushNow(FlushQueue.java:47)
at com.intellij.openapi.application.impl.FlushQueue$FlushNow.run(FlushQueue.java:190)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:776)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:727)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:746)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:976)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:843)
at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$8(IdeEventQueue.java:454)
at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:773)
at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$9(IdeEventQueue.java:453)
at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:822)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:501)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
```
```
IDE: IntelliJ IDEA (build #IU-203.5981.155, 30 Nov 2020 14:35)
OS: Windows 10 (10.0, amd64)
JRE: 11.0.9+11-b1145.21 (JetBrains s.r.o.)
JVM: 11.0.9+11-b1145.21 (OpenJDK 64-Bit Server VM)
```

---

*Imported from [IDEA-257531](https://youtrack.jetbrains.com/issue/IDEA-257531) · Type: Bug · Votes: 0*
*Comments, attachments, dates and reporter are not part of the export — follow the link above for the full history.*

Start at org.jetbrains.plugins.grails.runner.impl.BaseGrailsCommandLineState.startProcess and follow the process setup into GrailsCommandLineState, using the reported BaseOSProcessHandler warning as the symptom to reproduce. Compare a Grails run-app debug launch on the reported IntelliJ, Java, and Windows versions; done means the long-idle process no longer produces the reported exception or warning unexpectedly.

Written by the indexing model from the issue text.