Clone the git repository:

git clone https://github.com/strawberrymusicplayer/strawberry.git

Install dependencies:

doas pkg_add qt6 qt6ct qt6-qttools pkgconf boost glib2 php-sqlite3 gstreamer1 gstreamer1-plugins-bad gstreamer1-plugins-base gstreamer1-plugins-good gstreamer1-plugins-libav gstreamer1-plugins-ugly gstreamer1mm py3-gstreamer1
fftw3 fftw3-common fftw3-float libcdio libmtp libgpod gpodder libebur128 gettext-tools sparsehash liblastfm glew libmygpo-qt qtx11extras glib2 libiconv taglib icu4c kdsingleapplication ninja boost chromaprint

Build process:

cd strawberry
mkdir build
cd build
cmake -DENABLE_ALSA=OFF ..
doas ln -s /usr/local/lib/libtag.so.13.1 /usr/lib/libtag.so
make -j $(sysctl -n hw.ncpu)
doas make install

As mentioned, it builds, installs and launches without error. However, there is no audio.
The default audio server on OpenBSD is sndio. Other media players like mpv, vlc, Clementine and audacious all work flawlessly.

The options for audio output in the settings are:

• Output to a sound card via sndio
• Wrapper audio sink for automatically detected audio sink
• Fake audio renderer
• Virtual audio sink for internal process communication
• Automatically select

None of these options result in audio. The first two crash the application. The next two options appear to be playing the audio files but, without audio.

Is there a way that I can build Strawberry (build flags, options etc) that will allow it to use the sndio audio server and output audio?