Using gdb against Element-Desktop

Occasionally it is useful to be able to connect to a running Element-Desktop with gdb, or to analayze a coredump. For this, you will need debug symbols.

1. If you don't already have the right version of Element-Desktop (eg because you are analyzing someone else's coredump), download and unpack the tarball from https://packages.element.io/desktop/install/linux/. If it was a nightly, your best bet may be to download the deb from https://packages.element.io/debian/pool/main/e/element-nightly/ and unpack it.

2. Figure out which version of Electron your Element-Desktop is based on. The best way to do this is to figure out the version of Element-Desktop, then look at yarn.lock for the corresponding version. There should be an entry starting electron@, and under it a version line: this will tell you the version of Electron that was used for that version of Element-Desktop.

3. Go to Electron's releases page and find the version you just identified. Under "Assets", download electron-v<version>-linux-x64-debug.zip (or, the -debug zip corresponding to your architecture).

4. The debug zip has a structure like:

   .
   ├── debug
   │   ├── chrome_crashpad_handler.debug
   │   ├── electron.debug
   │   ├── libEGL.so.debug
   │   ├── libffmpeg.so.debug
   │   ├── libGLESv2.so.debug
   │   └── libvk_swiftshader.so.debug
   ├── LICENSE
   ├── LICENSES.chromium.html
   └── version
   

   Take all the contents of debug, and copy them into the Element-Desktop directory, so that electron.debug is alongside the element-desktop-nightly executable.

5. You now have a thing you can gdb as normal, either as gdb --args element-desktop-nightly, or gdb element-desktop-nightly core.