Question about building fflas_ffpack

[Zachary Scherr]

In an attempt to learn a little bit about sage's build system I was playing around with building various packages today.  From a fresh git clone I can build the developer branch of my Mac with homebrew without any issues.  However, if I just run

make fflas_ffpack

after going through the usual steps with source .homebrew-build-env and ./configure then it crashes pretty quickly with the message:

[fflas_ffpack-2.4.3] *******************************************************************************

[fflas_ffpack-2.4.3]  ERROR: BLAS not found!

[fflas_ffpack-2.4.3]

[fflas_ffpack-2.4.3]  BLAS routines are required for this library to compile. Please

[fflas_ffpack-2.4.3]  make sure BLAS are installed and specify its location with the option

[fflas_ffpack-2.4.3]  --with-blas-libs=<libs> and if necessary --with-blas-cflags=<cflags>

[fflas_ffpack-2.4.3]  when running configure.

[fflas_ffpack-2.4.3] *******************************************************************************

I'm just curious as to why make build works to build fflas_ffpack but if I try to build it on its own then it fails.  I've included the log file, but I'm guessing there's some easy explanation. 

[John H Palmieri]

That's funny, I just hit the same problem. The solution is to run 'make toolchain' first. (This should happen automatically when you run make, which is why that succeeds.) See https://trac.sagemath.org/ticket/30721.