[armadillo] Add dependent port superlu on osx

[JackBoosY]

Official document:

### 4: Compilers and External Dependencies

Armadillo makes extensive use of template meta-programming and many other advanced C++ features. As such, C++ compilers which do not fully implement the C++ standard may not work correctly.

The functionality of Armadillo is partly dependent on other libraries: LAPACK, BLAS (preferably OpenBLAS), ARPACK and SuperLU. LAPACK and BLAS are used for dense matrices, while ARPACK and SuperLU are used for sparse matrices.

Armadillo can work without the above libraries, but its functionality will be reduced. Basic functionality will be available (eg. matrix addition and multiplication), but operations like eigen decomposition or matrix inversion will not be. Matrix multiplication (mainly for big matrices) may not be as fast.

As Armadillo is a template library, we recommended that optimisation is enabled during compilation of programs that use Armadillo. For example, for GCC and Clang compilers use -O2 or -O3

Related: #10767 #11037 #11018 #10476 #11016 #11036 #11020 #10295 #8871 #11058 #11017 #11057 #9550 #11010 #11055 #11057 #11058 #10943.

[JackBoosY]

@strega-nil Please merge this PR first.

Thanks.

[cenit]

Why superlu is a dependency (and not a feature maybe) for armadillo only for osx?

Also, I'm not sure superlu port is ok.
On macOS it's best to avoid installing openblas, since the Accelerate framework (native in osx) includes a better version and is already available. So superlu in its control file should depend (like any other port) on openblas(!osx)...

[BillyONeal]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[cbezault]

Like @cenit pointed out superlu definitely needs to not install OpenBLAS on macOS and use the Accelerate framework instead.

Looking at the doc @JackBoosY is quoting from I'm also surprised we don't need superlu on other platforms. Perhaps OpenBLAS provides some of the same functions as superlu (OpenBLAS is known to do that kind of stuff).

[cenit]

@cbezault Exactly. Please do not merge confused pr only to apparently fix things.

[BillyONeal]

@cbezault Exactly. Please do not merge confused pr only to apparently fix things.

It doesn't seem like a confused PR, it seems like a PR correctly documenting the status quo, since the only way this passed before was accidentally getting superlu on the box first?

[cenit]

1. Superlu is not mandatory for armadillo
2. If it were mandatory, why is it only for osx?
3. This pr is indirectly installing OpenBLAS on OS X, which should be avoided

[BillyONeal]

1. And yet, the build for it is failing due to a missing superlu header.
2. No idea.
3. Maybe, but the PR seems to be documenting the status quo rather than changing something here.

[cenit]

1. This should be investigated, not hidden in a confused pr, sorry for insisting
2. That’s the problem. See 1
3. Armadillo was working on OS X well before the very recent superlu port...

[BillyONeal]

3. Armadillo was working on OS X well before the very recent superlu port...

Other ports vendored superlu. For example hypre.

[strega-nil]

I think this is not correct; it works fine without updating armadillo right now on my macbook, this seems like an issue with a different port that's getting installed. Can we just skip it in CI for now and try and figure it out later?

[BillyONeal]

@strega-nil You are the mac wizard :)

[cbezault]

A vendored superlu is a plausible explanation for what's going on but I have to agree with @cenit, it's just an unknown right now. I'd rather see this port get skipped and we actually fix it right.

[Neumann-A]

  message(STATUS "     MKL_FOUND = ${MKL_FOUND}"     )
  message(STATUS "  ACMLMP_FOUND = ${ACMLMP_FOUND}"  )
  message(STATUS "    ACML_FOUND = ${ACML_FOUND}"    )
  message(STATUS "OpenBLAS_FOUND = ${OpenBLAS_FOUND}")
  message(STATUS "   ATLAS_FOUND = ${ATLAS_FOUND}"   )
  message(STATUS "    BLAS_FOUND = ${BLAS_FOUND}"    )
  message(STATUS "  LAPACK_FOUND = ${LAPACK_FOUND}"  )

include(ARMA_FindARPACK)
message(STATUS "ARPACK_FOUND = ${ARPACK_FOUND}")

include(ARMA_FindSuperLU5)
message(STATUS "SuperLU_FOUND = ${SuperLU_FOUND}")

Armadillo's CMakeLists.txt probably needs to be patched to put all those dependencies behind an option

BLAS and LAPACK are already patched

[BillyONeal]

#11091 just adds to the baseline.

[ras0219-msft]

Since this is the underlying issue causing the mlpack:x64-osx regression, I've added a patch that disables all the dynamic dependency enablement. Through future PRs, these individual dependencies can be reenabled via features :)

[ras0219-msft]

Note: the OSX CI check appears offline, so this should not be merged until that is resolved.

[Neumann-A]

Since this is the underlying issue causing the mlpack:x64-osx regression

It is one reason. The other reason is that some port is vendoring SuperLU. So somebody needs to find the port doing it

[BillyONeal]

Note: the OSX CI check appears offline, so this should not be merged until that is resolved.

It's part of the 'microsoft.vcpkg' check now :)