Frequent crash in VM, possible race condition

[zvonler-sfw]

Have been doing development of an app in Rocky 8 virtual machine, and can frequently reproduce a crash when trying to show the FileSave or FileOpen dialog a second time after cancelling it the first time. The crash seems never to happen when running the same code natively on MacOS, and the app is generally a little sluggish inside the VM hence the guess at the cause being a race.

This repo includes a very simple app I can use to reproduce the issue, happy to provide more details as this has been difficult to work around.

Here is the error log I get when it crashes:
error_log.txt

[davep]

You might need to explain what a "Rocky 8 virtual machine" is and what impact that might have. Unfortunately the log you provide looks garbled and unreadable and the link to the reproduction is 404.

It would also be helpful to know:

• Python version
• Textual version

[davep]

On the surface this sounds similar to Textualize/textual#6528 -- what happens if you pin Textual to < 8 as suggested in that issue?

[davep]

Got it. I understand if you don't want to debug it, but if you do want to read more, lima can be installed with homebrew and can have a Rocky 8 Linux virtual machine running on your Mac in just a few minutes. lima-vm/lima

Thanks, I'll keep that in mind, but I can't promise if or when I'll get the time to set this up.

[zvonler-sfw]

FWIW, this patch seems to fix the crash completely:

diff --git a/src/textual_fspicker/parts/directory_navigation.py b/src/textual_fspicker/parts/directory_navigation.py
index 31a08d4..dc4d097 100644
--- a/src/textual_fspicker/parts/directory_navigation.py
+++ b/src/textual_fspicker/parts/directory_navigation.py
@@ -371,12 +371,15 @@ class DirectoryNavigation(OptionList):
     @property
     def _styles(self) -> DirectoryEntryStyling:
         """The styles to use for a directory entry."""
-        return DirectoryEntryStyling(
-            self.get_component_rich_style("directory-navigation--hidden"),
-            self.get_component_rich_style("directory-navigation--name", partial=True),
-            self.get_component_rich_style("directory-navigation--size", partial=True),
-            self.get_component_rich_style("directory-navigation--time", partial=True),
-        )
+        try:
+            return DirectoryEntryStyling(
+                self.get_component_rich_style("directory-navigation--hidden"),
+                self.get_component_rich_style("directory-navigation--name", partial=True),
+                self.get_component_rich_style("directory-navigation--size", partial=True),
+                self.get_component_rich_style("directory-navigation--time", partial=True),
+            )
+        except KeyError:
+            return DirectoryEntryStyling(Style(), Style(), Style(), Style())
 
     def _repopulate_display(self) -> None:
         """Repopulate the display of directories."""

[davep]

It would be great to know what the actual cause of the problem is, but that's a safe enough change that I'm happy to include it if it helps in your environment. Would you like to do a PR for it?

[zvonler-sfw]

Sure, happy to. Glad to find a way to use your picker again, it's a really nice widget. BTW, I did just try with textual pinned to 7.5.0 and got the same crash in my VM.