This is based on previous work for switching between BLAS and LAPACK
implementation in Debian[1] and Gentoo[2]. The goal is to have one way
to depend on the BLAS/LAPACK libraries that all packages must use. The
attrs “blas” and “lapack” are used to represent a wrapped BLAS/LAPACK
provider. Derivations that don’t care how BLAS and LAPACK are
implemented can just use blas and lapack directly. If you do care what
you get (perhaps for some CPP), you should verify that blas and lapack
match what you expect with an assertion.
The “blas” package collides with the old “blas” reference
implementation. This has been renamed to “blas-reference”. In
addition, “lapack-reference” is also included, corresponding to
“liblapack” from Netlib.org.
Currently, there are 3 providers of the BLAS and LAPACK interfaces:
- lapack-reference: the BLAS/LAPACK implementation maintained by netlib.org
- OpenBLAS: an optimized version of BLAS and LAPACK
- MKL: Intel’s unfree but highly optimized BLAS/LAPACK implementation
By default, the above implementations all use the “LP64” BLAS and
LAPACK ABI. This corresponds to “openblasCompat” and is the safest way
to use BLAS/LAPACK. You may received some benefits from “ILP64” or
8-byte integer BLAS at the expense of breaking compatibility with some
packages.
This can be switched at build time with an override like:
import <nixpkgs> {
config.allowUnfree = true;
overlays = [(self: super: {
lapack = super.lapack.override {
lapackProvider = super.lapack-reference;
};
blas = super.blas.override {
blasProvider = super.lapack-reference;
};
})];
}
or, switched at runtime via LD_LIBRARY_PATH like:
$ LD_LIBRARY_PATH=$(nix-build -E '(with import <nixpkgs> {}).lapack.override { lapackProvider = pkgs.mkl; is64bit = true; })')/lib:$(nix-build -E '(with import <nixpkgs> {}).blas.override { blasProvider = pkgs.mkl; is64bit = true; })')/lib ./your-blas-linked-binary
By default, we use OpenBLAS LP64 also known in Nixpkgs as
openblasCompat.
[1]: https://wiki.debian.org/DebianScience/LinearAlgebraLibraries
[2]: https://wiki.gentoo.org/wiki/Blas-lapack-switch
This package is hardly used in Nixpkgs. Why is it considered
sufficiently important to block a channel?
It's been blocking the nixpkgs-unstable for 8 days now, so removing it
from release*.nix.
Negative reasoning like `allBut` is a bad idea with an open world of
platforms. Concretely, if we add a new, quite different sort of
platform, existing packages with `allBut` will claim they work on it
even though they probably won't.
This commit removes all references to emacs24 with the exception of
emacs24-macports. The two folders in `pkgs/applications/editors` named
`emacs-24` and `emacs-24` are consolidated to a new `emacs` folder.
Various parts in nixpkgs also referenced `emacs24Packages` (pinned to
`emacs24`) explicitly where `emacsPackages` (non-pinned) is more
appropriate. These references get fixed by this commit too.
This was one of the ways to build packages, we are trying
hard to minimize different ways so it's easier for newcomers
to learn only one way.
This also:
- removes texLive (old), fixes#14807
- removed upstream-updater, if that code is still used it should be in
separate repo
- changes a few packages like gitit/mit-scheme to use new texlive
It is deprecated doesn't handle compressed modules, unlike its modern
counterpart kmod.
Add a compatibility alias to kmod for now in case someone is depending
on this in their scripts.
gcc42 was removed in commit 5add082ab8
("gcc-4.2: Remove") but there are still some references to it. Remove
those references to fix Hydra tarball job.
