On Wed, Nov 21, 2012 at 6:44 PM, Derek Gaston <friedmud@gmail.com> wrote:
I simply stated that the new system, for me, is frustrating.

Fair enough.
 
Since you are asking, let me give you an example:

In the old system, this was my libMesh workflow.

svn up
./configure && make -j24 && METHOD=dbg make -j24

Then, I would make a change in some file in libMesh and rebuild using:

make && METHOD=dbg make

Nothing is simpler than that.

Now let's examine the new system:

svn up
./bootstrap # if even possible
mkdir build_opt
cd build_opt
../configure --prefix=~/libmesh_install
make -j24
make install
cd ..
mkdir build_dbg
cd build_dbg
export METHOD=dbg
../configure --prefix=~/libmesh_install
make -j24
make install

The only difference between this and the former build system is the extra cd's (minor annoyance) and make install (nice new feature, IMHO, that was not present in the previous build system).
 
Then I go make a change to libMesh and need to do:

cd build_opt
make
make install
cd ..
cd build_dbg
export METHOD=dbg
make
make install

Every single change I must now go into two different directories to build AND I must run "make install" for each one.

Again, I don't see that much of a difference. Yes, cd'ing is a minor annoyance, but certainly not any kind of measurably time against building the code and something that is easily added to existing build scripts. And you still have to make twice with the previous system, so it's not like there's a big performance difference.
 
 "make install" BTW is a non-trivial operation. On slow network filesystems it can take a significant amount of time.

I'm surprised that you get any benefit out of make -j 24 then (vs. -j 12, say. I'm assuming you're using distcc). Even on a slow file system, I'd be surprised if make install was a significant percentage of the build time.
 
 We were trying to debug the PETSc issue we're having with the new build system yesterday... and holy smokes it is frustrating to make a tiny change then have to wait around while cd'ing to different directories and building and make installing.  It is FRUSTRATING.

Do you have timings or something? I'm not trying to be a jerk, but I find it hard to believe that your development cycle is suddenly measurably slower because of having to add a few cd's and make install into your build cycle.

Paul