Rickbude
commented
2 years ago I think I have hit the same (or at least a very similar) issue, but it manifests slightly differently. make scalapack succeeds in my case, but ld reveals there are undefined symbols, just like you:
#build (clean build directory, empty cache)
cmake .. -DBUILD_SHARED_LIBS=1
make -j24
ld lib/libscalapack.soOutputs:
ld: warning: cannot find entry symbol _start; not setting start address
ld: lib/libscalapack.so: undefined reference to `ompi_mpi_op_sum'
ld: lib/libscalapack.so: undefined reference to `MPI_Bcast'
ld: lib/libscalapack.so: undefined reference to `MPI_Op_create'
ld: lib/libscalapack.so: undefined reference to `MPI_Pack_size'
ld: lib/libscalapack.so: undefined reference to `MPI_Send'
ld: lib/libscalapack.so: undefined reference to `ompi_mpi_packed'
ld: lib/libscalapack.so: undefined reference to `MPI_Isend'
....This seems to easily be fixed by linking scalapack with MPI::MPI_C (or with ${MPI_C_LIBRARIES} for CMake < 3.9):
#At CMakeLists.txt line 247, change
target_link_libraries( scalapack ${LAPACK_LIBRARIES} ${BLAS_LIBRARIES})
#to
target_link_libraries( scalapack ${LAPACK_LIBRARIES} ${BLAS_LIBRARIES} ${MPI_C_LIBRARIES})For me this seems to work, but I don't if this would have any negative side effects, and have not tested this patch on Windows. So I am a bit hesitant to make a PR for this.
Sidenote: I hit this problem when trying to link with ScaLAPACK (imported with FetchContent_Declare). If you have a similar usecase, it is also possible to just add a patch in your own code and circumvent the problem that way. Here is a minimal example to demonstrate that:
#CMakeLists.txt
cmake_minimum_required(VERSION 3.14)
project(ScaLAPACK_TEST LANGUAGES C CXX Fortran)
#Enable fetching packages from git
include(FetchContent)
set(BUILD_SHARED_LIBS TRUE)
#Download and build ScaLAPACK 2.2.0 , commit from 7 July 2022
message(STATUS "Dowloading and building ScaLAPACK from source...")
FetchContent_Declare(referenceScaLAPACK
GIT_REPOSITORY https://github.com/Reference-ScaLAPACK/scalapack.git
GIT_TAG 637a6e5f2953263d4f05574c8d6037356a81b9ea
)
FetchContent_MakeAvailable(referenceScaLAPACK)
#Enable the following two lines to resolve build issues
#find_package(MPI)
#target_link_libraries(scalapack MPI::MPI_C)
add_executable(main main.cpp)
target_link_libraries(main scalapack)//main.cpp
int main(){
return 0;
}Without target_link_libraries(scalapack MPI::MPI_C) make main fails, and after enabling target_link_libraries(scalapack MPI::MPI_C) make main succeeds.
weslleyspereira
drhpc
This issue covers apparently very basic build trouble on the path to package ScaLAPACK for pkgsrc, so I hope an issue is warranted. I do have changes to suggest, too, convering handling of dependencies (.pc file), but first the current version should at least build …
I might be too obvious, but I have trouble building scalapack 2.2.0. CMake lokates my compiler/MPI setup just fine:
But it doesn't even try to link to MPI, apparently:
and, obviously
Shouldn't there be a reference to libmpi?
I also don't see e.g.
MPI_LIBRARIES,MPI_LINK_FLAGS, or anything like that used in CMakeLists.txt. I guess it is supposed to make more use of the MPI compiler wrappers? How is this supposed to work? (Note: Don't be fooled by the cvs-20210222 name, it is a current checkout of the pkgsrc tree, which I am trying to add scalapack to.)When I tried to hack in use of
MPI_LIBRARIES, the main MPI symbols were resolved, but I still had some missing ones at some stage. So, before I dive too deep, I hoped to get some clarification that the build should normallyjust workor that I'm doing something wrong. I did have a working draft installation of scalapack-2.1.0 before. I might have to revisit why that worked.