I thought that I’d report this, in case it’s not the expected behaviour: In Panda3D 1.9.4 (my custom build, at least), using OpenAL, attempting to alter the volume of the sound-effect manager after a sound has failed to load may result in the program immediately exiting with “code 139” (I believe that it was).
There are some complications to this report: The sounds that were failing to load were, I think, being (unsuccessfully) loaded both before and after loading a level, but the crash was occurring only after.
I would think that the unsuccessful loads were unrelated to the crash, save for one thing:
The reason that the sounds were failing to load was simply that the files were simply not present–I discovered this possible-bug while doing some testing that occurred between removing (by renaming) some sound files and replacing them with new ones, as I recall. Once the files were replaced, and the sounds were thus no longer failing to load, the crash disappeared.
 In case it’s relevant, I was setting the volume on “base.sfxManagerList”.