Arch Linux

works flawlessly here, I suspect its an issue with your environment or something that your environment is using

If I downgrade intellij to 2:2019.1.3-2 it works.

@anthraxx, strange, what could it be...

does it work if you run it via:
IDEA_JDK="/usr/lib/jvm/java-8-openjdk/"
while having java8 installed?

It does not.

I get thousand of assertions in the console, here's an example:

2019-09-06 12:13:45,675 [ 12562] ERROR - lij.ui.ColoredTreeCellRenderer - IntelliJ IDEA 2019.2.1 Build #IC-192.6262.58
2019-09-06 12:13:45,675 [ 12562] ERROR - lij.ui.ColoredTreeCellRenderer - JDK: 1.8.0_222; VM: OpenJDK 64-Bit Server VM; Vendor: Oracle Corporation
2019-09-06 12:13:45,675 [ 12562] ERROR - lij.ui.ColoredTreeCellRenderer - OS: Linux
2019-09-06 12:13:45,676 [ 12563] ERROR - lij.ui.ColoredTreeCellRenderer - Last Action:
2019-09-06 12:13:45,866 [ 12753] ERROR - lij.ui.ColoredTreeCellRenderer - @NotNull method com/intellij/util/ui/UIUtil.getTreeForeground must not return null
java.lang.IllegalStateException: @NotNull method com/intellij/util/ui/UIUtil.getTreeForeground must not return null
at com.intellij.util.ui.UIUtil.$$$reportNull$$$0(UIUtil.java)
at com.intellij.util.ui.UIUtil.getTreeForeground(UIUtil.java:3757)
at com.intellij.ui.treeStructure.Tree.getForeground(Tree.java:172)
at com.intellij.ui.ColoredTreeCellRenderer.rendererComponentInner(ColoredTreeCellRenderer.java:106)
at com.intellij.ui.ColoredTreeCellRenderer.getTreeCellRendererComponent(ColoredTreeCellRenderer.java:52)
at com.intellij.openapi.vcs.changes.ui.ChangesTree$MyTreeCellRenderer.getTreeCellRendererComponent(ChangesTree.java:637)
at com.intellij.ui.tree.ui.DefaultTreeUI.getRenderer(DefaultTreeUI.java:135)
at com.intellij.ui.tree.ui.DefaultTreeUI.access$500(DefaultTreeUI.java:39)
at com.intellij.ui.tree.ui.DefaultTreeUI$1.getNodeDimensions(DefaultTreeUI.java:326)
at javax.swing.tree.AbstractLayoutCache.getNodeDimensions(AbstractLayoutCache.java:492)
at javax.swing.tree.VariableHeightLayoutCache$TreeStateNode.updatePreferredSize(VariableHeightLayoutCache.java:1360)
at javax.swing.tree.VariableHeightLayoutCache.rebuild(VariableHeightLayoutCache.java:738)
at javax.swing.tree.VariableHeightLayoutCache.setModel(VariableHeightLayoutCache.java:109)
at javax.swing.plaf.basic.BasicTreeUI.setModel(BasicTreeUI.java:412)
at javax.swing.plaf.basic.BasicTreeUI$Handler.propertyChange(BasicTreeUI.java:3414)
at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
at java.awt.Component.firePropertyChange(Component.java:8434)
at javax.swing.JTree.setModel(JTree.java:885)
at com.intellij.openapi.vcs.changes.ui.ChangesListView.updateModel(ChangesListView.java:91)
at com.intellij.openapi.vcs.changes.ChangesViewManager.lambda$null$9(ChangesViewManager.java:393)
at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:312)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.doRun(LaterInvocator.java:433)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.runNextEvent(LaterInvocator.java:416)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:399)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:817)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:766)
at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$8(IdeEventQueue.java:405)
at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:704)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:404)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

yeah it definitively requires 11. sometimes intellij patches weird stuff in their bundled JRE.
Interesting that you are hit buy this bug and others are not.

Does it change anything if you run it normally but with
export _JAVA_AWT_WM_NONREPARENTING=1

You can try to open a bug report at intellij as it shouldn't be that buggy just with a regular openjdk.

PS: Are you really updating once every 3 months? x_X

I tried to open it like this:

_JAVA_AWT_WM_NONREPARENTING=1 IDEA_JDK="/usr/lib/jvm/java-11-openjdk" idea

But it did not work.

https://youtrack.jetbrains.com/issue/IDEA-222127