Re: OpenBLAS

[Pjotr Prins]

On Sat, Oct 08, 2016 at 10:13:39PM +0200, Federico Beffa wrote:
> Hi,
> 
> I'm wondering why our OpenBLAS package is built with the flag
> "NO_LAPACK=1". It is my understanding that with this optional flag
> OpenBLAS doesn't include LAPACK, while without this flag and by
> default it does include the LAPACK functions.  In the latter case
> OpenBLAS could be used by a larger number of packages which do require
> LAPACK functions.
> 
> https://github.com/xianyi/OpenBLAS/issues/203

NO_LAPACK=0 does not use external libs. NO_LAPACK=1 uses external
liblapack. They both cover LAPACK functionality.

NO_LAPACK=1 is the conservative choice - it still is what most
software has been developed against today.

OpenBLAS has merged LAPACK code and they have been changing things,
claiming their version is better performing. But since it is less well
tested, new bugs are quite possible. I have hit at least one OpenBLAS
bug, so far.

Personally I think we should have both options in Guix, but we should
probably keep defaulting to NO_LAPACK=1.

Pj.