Dear all, It is now clear that scons can cut down overall building time by 1/3 or even 1/2, but a trivial null build will take from 24s to 4m.
This is because scons is an 'overall' build process. It gathers all file information (checking contents rather than time stamp) and decide what to do. Autotools' recursive-make approach only cares about current and sub directories, and is faster in this regard. (BTW, use scons -u to build only a subdirectory). I am too new to scons to give a full solution here. Here are some of my opinions: 1. The check content (md5) approach is better than autotools since time stamp can be easily changed and may trigger unnecessary rebuilds. Using scons should reduce the chance of such a waste of time. Note that one can let scons check time stamp, this should reduce starting time a bit. 2. Currently, I use the default settings of scons (like copying files to build directory) to ganrantee correct build. I will try to change to non-copy if things go well. 3. Waf is a KDE variant of scons. It is a product of insufficient communication between KDE and scons developers. I personally hate such branched projects since they make users (us) difficult to choose (like emacs/xemacs) and may lead to wasted efforts (like klyx?) Waf aims to fix many concerns of scons, one of which is the starting time. I will give waf a try later. I will also ask the scons-user list for an opinion. Cheers, Bo
