recently tried to add ALSA support to core-image-minimal . by adding following lines into local.conf: MACHINE_FEATURES+="alsa" DISTRO_FEATURES+="alsa" CORE_IMAGE_EXTRA_INSTALL+="alsa-utils" but got error of which I have attached image.

please guide me what should I do to solve it.

Check available sound cards in your system. 'aplay -L' It seems you have no suitable default one for speaker-test to use. If you have sound cards in your machine and want to point out another one that speaker-test shall use you can pass that as an argument. https://linux.die.net/man/1/speaker-test

/Peter