Linking chgres_cube failed on macOS Monterey

[ywangwof]

I am trying to build ufs-srweather-app using script devbuild.sh on macOS Monterey using GNU compilers and got the following message

[ 59%] Linking Fortran executable chgres_cube
ld: library not found for -lmpi_cxx
collect2: error: ld returned 1 exit status
make[5]: *** [sorc/chgres_cube.fd/chgres_cube] Error 1
make[4]: *** [sorc/chgres_cube.fd/CMakeFiles/chgres_cube.dir/all] Error 2
make[3]: *** [all] Error 2
make[2]: *** [sorc/UFS_UTILS/src/UFS_UTILS-stamp/UFS_UTILS-build] Error 2
make[1]: *** [sorc/CMakeFiles/UFS_UTILS.dir/all] Error 2
make: *** [all] Error 2

hpc-stack has been installed with openmpi 4.1.2 successfully and both ufs_model and upp are built without a problem.

Anyone has the same problem before and a solution? Thanks.

[natalie-perlin]

@ywangwof - thank you for sharing your experience, and the details you provided - all are needed! I'll be looking into it. Few more questions on your setup: are you using Mac with M1 or Intel chip? What branch of ufs-srweather-app are you using (develop, release/public-v2.1.0)?

[ywangwof]

My Mac is with intel chip and the ufs-srweather-app branch is develop by this commit.

• baf4df1 - (2023-04-07) [develop] Point source pre-combine ([develop] Point source pre-combine #708)

[ywangwof]

I found the problem is that library -lmpi_cxx is not in the linking paths for program chgres_cube (it is installed in $HPC_INSTALL_DIR/gnu-12.2.0/openmpi/4.1.2/lib). There are two solutions

1. Copy/Link the library from $HPC_INSTALL_DIR/gnu-12.2.0/openmpi/4.1.2/lib/libmpi_cxx.dylib to $BREW/Cellar/gcc/12.2.0/bin/../lib/gcc/current/gcc/x86_64-apple-darwin21/12/../../../.
2. Put $HPC_INSTALL_DIR/gnu-12.2.0/openmpi/4.1.2/lib to the linking paths of program chgres_cube.

Solution 1 is not generalized for all users. About solution 2, I do not know how to modify the CMakeList.txt file for it to work. Any suggestion? Thanks.

[natalie-perlin]

@ywangwof - I do attempt to reproduce your error.
As to the library not in the path: after you load the modulefile,
module load build_macos_gnu
there is a message asking you to export an LDFLAGS variable:
export LDFLAGS+=" -L$MPI_ROOT/lib "
(It is likely that the message in the modulefiles needs to be corrected to display exactly the one shown above)

This is where the library lmpi_cxx is expected to be found. For the MacOS, you are likely to have the following files in your $MPI_ROOT/lib directory: libmpi_cxx.la, libmpi_cxx.dylib

[ywangwof]

Thanks @natalie-perlin. Your answer explains the problem. I was using devbuild.sh to build the programs, which load the module automatically and it does not give users a chance to read the output message from module "build_macos_gnu".

I am wondering whether it is possible to set the environment variable LDFLAGS in the script devbuild.sh automatically after it loads the module file on macOS?

[natalie-perlin]

@ywangwof - thanks for letting me know it became more clear!
The documentation for building the SRW v2.1 on MacOS indeed suggests using CMake approach vs. devbuils.sh .
And yes, adding the LDFLAGS by default sounds like a better approach, so I'd consider implementing these changes when possible. Thank you for your involvement!