Thanks for testing, and sorry, this was the wrong information. There is no override of the config directory by the environment variable. $ALSA_CONFIG_PATH specifies the main config file, but it can't change the default config path that other files may include. After thinking of this problem and the current situation again, I concluded that removing the new stuff would be better so that the old alsa-lib can still work somehow. Although the usage of the old alsa-lib with the new config is clearly invalid, your use case implies that it's widely deployed, and we should avoid breakage. I'll fix up the upstream code and backport.