Every headless test app built `GamePlugins`, whose `SoundPlugin` opened the default output device unless `$WOW_NOSOUND` or `$WOW_CAPTURE` was set, and no test run sets either. Under nextest that is one CoreAudio client and speaker stream per test process. With a few runs going at once, `coreaudiod` sat near 300% CPU, every sound on the machine crackled, and each test blocked on the audio server's connect.
A test build now takes the existing silent path, so its mixer is `None`, as with no device.
Test: `a_test_client_opens_no_audio_device`. With the change undone it fails on a machine with a speaker, taking 96 s; with it, the test passes in 0.06 s.
Fixes#2380🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Sam Sung
fbc90b9bbf