The KMix package contains a KF6 based Sound Mixer application.
This package is known to build and work properly using an LFS 12.4 platform.
Download (HTTP): https://download.kde.org/stable/release-service/25.08.0/src/kmix-25.08.0.tar.xz
Download MD5 sum: b0cd9feac7bc4266fe46630ac39848ea
Download size: 1.1 MB
Estimated disk space required: 28 MB
Estimated build time: 0.2 SBU (using parallelism=4)
Install KMix by running the following commands:
mkdir build &&
cd build &&
cmake -D CMAKE_INSTALL_PREFIX=$KF6_PREFIX \
-D CMAKE_BUILD_TYPE=Release \
-D BUILD_TESTING=OFF \
-W no-dev .. &&
make
This package does not come with a test suite.
Now, as the root user:
make install