Error:
"Kernel driver is active, or device is claimed by second instance of librtlsdr.
In the first case, please either detach or blacklist the kernel module
(dvb_usb_rtl28xxu), or enable automatic detaching at compile time."

Problem:
Raspberry Pi OS "bookworm" (Debian version 12) ignores /etc/modprobe.d/blacklist.conf

Solution:
cmake ../ -DINSTALL_UDEV_RULES=ON -DDETACH_KERNEL_DRIVER=ON

Hints:
speaker-test -c2 -twav
Listen to a radio station with
rtl_fm -f 94.4M -s 192000 -r 48000 | aplay -r 48 -f S16_LE -t raw -c 1
or
rtl_fm -f 94.4M -s 192000 -r 48000 | play -t raw -r 48k -es -b 16 -c 1 -V1 -