Crash in release builds if I open a child window and close the main window

[nyanpasu64]

I'm running this repo, latest main d385ace, on Linux.

If I cargo run --release, then click "Open in New Window" or "Show Other Window" (since they're non-modal), then close the main window with the child still open, the process will segfault.

• There is an inconsistent delay before the program crashes. In the case of "Show Other Window", the segfault happens after the "Call method on parent window" button is grayed out.
• The segfault does not occur on debug builds of Cargo+Flutter through cargo run. (I don't know how to control Rust and Flutter debugging separately.)

Stack trace is as follows (sadly it's a bit useless since libflutter_linux_gtk.so has no symbols):

(gdb) bt
#0  0x00007ffff7dc5bf6 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#1  0x00007ffff7db5526 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#2  0x00007ffff7dc6705 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#3  0x00007ffff7f43934 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#4  0x00007ffff7b4bf29 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#5  0x00007ffff7c4ccb6 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#6  0x00007ffff7d56197 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#7  0x00007ffff7b26ee6 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#8  0x00007ffff7b25579 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#9  0x00007ffff7b3cb81 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#10 0x00007ffff768d073 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#11 0x00007ffff7692f46 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#12 0x00007ffff768cf11 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#13 0x00007ffff7692715 in  () at /home/nyanpasu64/code/nativeshell-examples/target/release/lib/libflutter_linux_gtk.so
#14 0x00007ffff6494259 in start_thread () at /usr/lib/libpthread.so.0
#15 0x00007ffff63b65e3 in clone () at /usr/lib/libc.so.6

Flutter version:

Flutter 2.3.0-17.0.pre.412 • channel master • https://github.com/flutter/flutter.git
Framework • revision 66b8f601e8 (62 minutes ago) • 2021-06-20 19:04:02 -0400
Engine • revision 1eb8a34a39
Tools • Dart 2.14.0 (build 2.14.0-228.0.dev)

System info:

Operating System: Arch Linux
KDE Plasma Version: 5.22.1
KDE Frameworks Version: 5.83.0
Qt Version: 5.15.2
Kernel Version: 5.12.11-zen1-1-zen (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GT 730/PCIe/SSE2

[knopp]

Hi, this is a known issue, it is tracked here: flutter/flutter#84908
The PR to fix it is being discussed here: flutter/engine#26835