[Bug] After updating to 0.18.0 Agents are extremely slow

[maxentric-aplymoth]

After the latest updates, Agents are extremely slow, thinking for extremely long time, even the moderate ones. Tasks that used to take 10-15 minutes, now takes several hours. Mostly tested with GPT 5.4-medium.

[iloveeclipse]

Could be GPT only issue. I tried today Claude Opus 4.7 and GPT 5.5 for same task (code review), later was really slow. It printed sentences in the "thinking" mode word by word, as it would really think :)

[jdneo]

I did not notice this with GPT 5.4-medium, is the behavior still the same now?

Or, do you observe the pattern that: chat view rendered smoothly at the beginning, and when more and more elements added, it becomes slow?

[ethanyhou]

Hi @maxentric-aplymoth, and @iloveeclipse,

Thanks for the feedback. We’re looking into this issue. Please stay tuned.

[ethanyhou]

Hi @iloveeclipse,

I'm currently investigating this issue and have tried several fixes to reduce the overhead of rendering the thinking block, but none of them have been effective. One thing I noticed is that the thinking block always becomes slow or gets stuck after the following error occurs:

!ENTRY org.eclipse.ui.console 4 120 2026-05-29 22:20:05.286
!MESSAGE fixed width: false
!STACK 0
org.eclipse.jface.text.BadLocationException: 244
	at org.eclipse.jface.text.TreeLineTracker.offsetByLine(TreeLineTracker.java:335)
	at org.eclipse.jface.text.TreeLineTracker.getLineOffset(TreeLineTracker.java:1101)
	at org.eclipse.jface.text.AbstractLineTracker.getLineOffset(AbstractLineTracker.java:252)
	at org.eclipse.jface.text.AbstractDocument.getLineOffset(AbstractDocument.java:868)
	at org.eclipse.ui.internal.console.ConsoleDocument.getLineOffset(ConsoleDocument.java:59)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.getLineOffset(ConsoleDocumentAdapter.java:354)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.getOffsetAtLine(ConsoleDocumentAdapter.java:332)
	at org.eclipse.swt.custom.StyledTextRenderer.getTextLayout(StyledTextRenderer.java:1099)
	at org.eclipse.swt.custom.StyledTextRenderer.getTextLayout(StyledTextRenderer.java:984)
	at org.eclipse.swt.custom.StyledTextRenderer.calculate(StyledTextRenderer.java:306)
	at org.eclipse.swt.custom.StyledText.getVerticalScrollOffset(StyledText.java:5066)
	at org.eclipse.swt.custom.StyledText.getOffsetAtPoint(StyledText.java:4224)
	at org.eclipse.swt.custom.StyledText.getOffsetAtPoint(StyledText.java:4176)
	at org.eclipse.swt.custom.StyledText.setCaretLocations(StyledText.java:8522)
	at org.eclipse.swt.custom.StyledText.setCaretLocations(StyledText.java:8479)
	at org.eclipse.swt.custom.StyledText.updateSelection(StyledText.java:10865)
	at org.eclipse.swt.custom.StyledText.handleTextChanged(StyledText.java:6120)
	at org.eclipse.swt.custom.StyledText$5.textChanged(StyledText.java:5442)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.documentChanged(ConsoleDocumentAdapter.java:588)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged2(AbstractDocument.java:739)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged(AbstractDocument.java:708)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged(AbstractDocument.java:692)
	at org.eclipse.jface.text.AbstractDocument.fireDocumentChanged(AbstractDocument.java:766)
	at org.eclipse.jface.text.AbstractDocument.replace(AbstractDocument.java:1091)
	at org.eclipse.jface.text.AbstractDocument.replace(AbstractDocument.java:1109)
	at org.eclipse.ui.internal.console.ConsoleDocument.replace(ConsoleDocument.java:74)
	at org.eclipse.ui.internal.console.IOConsolePartitioner.trim(IOConsolePartitioner.java:1216)
	at org.eclipse.ui.internal.console.IOConsolePartitioner.checkBufferSize(IOConsolePartitioner.java:438)
	at org.eclipse.ui.internal.console.IOConsolePartitioner$QueueProcessingJob.processPendingPartitions(IOConsolePartitioner.java:808)
	at org.eclipse.ui.internal.console.IOConsolePartitioner$QueueProcessingJob.runInUIThread(IOConsolePartitioner.java:763)
	at org.eclipse.ui.progress.UIJob.lambda$0(UIJob.java:148)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4135)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3751)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:678)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:583)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:185)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:219)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:149)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:115)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:467)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:298)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:627)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1431)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1403)

!ENTRY org.eclipse.ui.console 4 120 2026-05-29 22:20:05.288
!MESSAGE fixed width: false
!STACK 0
org.eclipse.jface.text.BadLocationException: 245
	at org.eclipse.jface.text.TreeLineTracker.getLineInformation(TreeLineTracker.java:1153)
	at org.eclipse.jface.text.AbstractLineTracker.getLineInformation(AbstractLineTracker.java:228)
	at org.eclipse.jface.text.AbstractDocument.getLineInformation(AbstractDocument.java:873)
	at org.eclipse.ui.internal.console.ConsoleDocument.getLineInformation(ConsoleDocument.java:44)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.getLineInformation(ConsoleDocumentAdapter.java:249)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.getLine(ConsoleDocumentAdapter.java:226)
	at org.eclipse.swt.custom.StyledTextRenderer.getTextLayout(StyledTextRenderer.java:1098)
	at org.eclipse.swt.custom.StyledTextRenderer.getTextLayout(StyledTextRenderer.java:984)
	at org.eclipse.swt.custom.StyledTextRenderer.calculate(StyledTextRenderer.java:306)
	at org.eclipse.swt.custom.StyledText.getVerticalScrollOffset(StyledText.java:5066)
	at org.eclipse.swt.custom.StyledText.getOffsetAtPoint(StyledText.java:4224)
	at org.eclipse.swt.custom.StyledText.getOffsetAtPoint(StyledText.java:4176)
	at org.eclipse.swt.custom.StyledText.setCaretLocations(StyledText.java:8522)
	at org.eclipse.swt.custom.StyledText.setCaretLocations(StyledText.java:8479)
	at org.eclipse.swt.custom.StyledText.updateSelection(StyledText.java:10865)
	at org.eclipse.swt.custom.StyledText.handleTextChanged(StyledText.java:6120)
	at org.eclipse.swt.custom.StyledText$5.textChanged(StyledText.java:5442)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.documentChanged(ConsoleDocumentAdapter.java:588)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged2(AbstractDocument.java:739)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged(AbstractDocument.java:708)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged(AbstractDocument.java:692)
	at org.eclipse.jface.text.AbstractDocument.fireDocumentChanged(AbstractDocument.java:766)
	at org.eclipse.jface.text.AbstractDocument.replace(AbstractDocument.java:1091)
	at org.eclipse.jface.text.AbstractDocument.replace(AbstractDocument.java:1109)
	at org.eclipse.ui.internal.console.ConsoleDocument.replace(ConsoleDocument.java:74)
	at org.eclipse.ui.internal.console.IOConsolePartitioner.trim(IOConsolePartitioner.java:1216)
	at org.eclipse.ui.internal.console.IOConsolePartitioner.checkBufferSize(IOConsolePartitioner.java:438)
	at org.eclipse.ui.internal.console.IOConsolePartitioner$QueueProcessingJob.processPendingPartitions(IOConsolePartitioner.java:808)
	at org.eclipse.ui.internal.console.IOConsolePartitioner$QueueProcessingJob.runInUIThread(IOConsolePartitioner.java:763)
	at org.eclipse.ui.progress.UIJob.lambda$0(UIJob.java:148)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4135)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3751)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:678)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:583)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:185)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:219)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:149)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:115)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:467)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:298)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:627)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1431)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1403)

!ENTRY org.eclipse.ui.console 4 120 2026-05-29 22:20:05.289
!MESSAGE fixed width: false
!STACK 0
org.eclipse.jface.text.BadLocationException: 245
	at org.eclipse.jface.text.TreeLineTracker.offsetByLine(TreeLineTracker.java:335)
	at org.eclipse.jface.text.TreeLineTracker.getLineOffset(TreeLineTracker.java:1101)
	at org.eclipse.jface.text.AbstractLineTracker.getLineOffset(AbstractLineTracker.java:252)
	at org.eclipse.jface.text.AbstractDocument.getLineOffset(AbstractDocument.java:868)
	at org.eclipse.ui.internal.console.ConsoleDocument.getLineOffset(ConsoleDocument.java:59)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.getLineOffset(ConsoleDocumentAdapter.java:354)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.getOffsetAtLine(ConsoleDocumentAdapter.java:332)
	at org.eclipse.swt.custom.StyledTextRenderer.getTextLayout(StyledTextRenderer.java:1099)
	at org.eclipse.swt.custom.StyledTextRenderer.getTextLayout(StyledTextRenderer.java:984)
	at org.eclipse.swt.custom.StyledTextRenderer.calculate(StyledTextRenderer.java:306)
	at org.eclipse.swt.custom.StyledText.getVerticalScrollOffset(StyledText.java:5066)
	at org.eclipse.swt.custom.StyledText.getOffsetAtPoint(StyledText.java:4224)
	at org.eclipse.swt.custom.StyledText.getOffsetAtPoint(StyledText.java:4176)
	at org.eclipse.swt.custom.StyledText.setCaretLocations(StyledText.java:8522)
	at org.eclipse.swt.custom.StyledText.setCaretLocations(StyledText.java:8479)
	at org.eclipse.swt.custom.StyledText.updateSelection(StyledText.java:10865)
	at org.eclipse.swt.custom.StyledText.handleTextChanged(StyledText.java:6120)
	at org.eclipse.swt.custom.StyledText$5.textChanged(StyledText.java:5442)
	at org.eclipse.ui.internal.console.ConsoleDocumentAdapter.documentChanged(ConsoleDocumentAdapter.java:588)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged2(AbstractDocument.java:739)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged(AbstractDocument.java:708)
	at org.eclipse.jface.text.AbstractDocument.doFireDocumentChanged(AbstractDocument.java:692)
	at org.eclipse.jface.text.AbstractDocument.fireDocumentChanged(AbstractDocument.java:766)
	at org.eclipse.jface.text.AbstractDocument.replace(AbstractDocument.java:1091)
	at org.eclipse.jface.text.AbstractDocument.replace(AbstractDocument.java:1109)
	at org.eclipse.ui.internal.console.ConsoleDocument.replace(ConsoleDocument.java:74)
	at org.eclipse.ui.internal.console.IOConsolePartitioner.trim(IOConsolePartitioner.java:1216)
	at org.eclipse.ui.internal.console.IOConsolePartitioner.checkBufferSize(IOConsolePartitioner.java:438)
	at org.eclipse.ui.internal.console.IOConsolePartitioner$QueueProcessingJob.processPendingPartitions(IOConsolePartitioner.java:808)
	at org.eclipse.ui.internal.console.IOConsolePartitioner$QueueProcessingJob.runInUIThread(IOConsolePartitioner.java:763)
	at org.eclipse.ui.progress.UIJob.lambda$0(UIJob.java:148)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4135)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3751)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:678)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:583)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:185)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:219)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:149)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:115)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:467)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:298)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:627)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1431)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1403)

Do you have any insights? Thanks for any suggestions.

[iloveeclipse]

Just curious: how an error on Console update affects thinking block performance? I don't see any pointers to the Copilot code in the error stack? Or is the listener org.eclipse.swt.custom.StyledText$5.textChanged(StyledText.java:5442) added by Copilot? Why do you listen to console styled text?

Beside this, the code runs in UI thread, it is exclusive and if some Copilot code tries to use UI thread at same time, it is a bottleneck of course. Not sure how much that all related to thinking blocks.