mercurial svn app is also called hg; mercurial app can be installed using your package manager 
automake package must be installed; remove alsa packages before installing hg 
install kernel source and kernel headers for your kernel; uname -r for kernel version
for ubuntu:  apt-get install build-essential     installs kernel sources
ubuntu build alsa sources: sudo apt-get install build-essential linux-headers-`uname -r` libncurses5-dev automake autoconf
use 'hg clone' command to download the alsa cvs source files  at http://alsa-project.org/download.php   at the hg repository link on this page; 
these are the files you need to download: alsa-drivers, alsa-kernel, alsa-libs, alsa-utils
http://hg-mirror.alsa-project.org/   ;read the entire page too
alsa driver needs alsa kernel to compile: 'hg clone http://hg-mirror.alsa-project.org/alsa-kernel alsa-kernel'
use ./hgcompile on all the alsa sources and not ./configure