CFD | OpenFOAM | gcc : error: unrecognized command line option ‘--showme:link’; did you mean ‘--force-link’?

Error

Error 1

• gcc: error: unrecognized command line option ‘--showme:link’; did you mean ‘--force-link’?

The error message you are seeing, gcc: error: unrecognized command line option ‘--showme:link’; did you mean ‘--force-link’?, indicates that the GCC compiler does not have an option with that specific name.

vim OpenFOAM-13/etc/bashrc

• export WM_MPLIB=INTELMPI #SYSTEMOPENMPI

Error 2

• /usr/bin/ld: cannot find -lmpi

gcc -m64 -fPIC -m64 ... /openfoam13/ThirdParty-13/Zoltan-3.90/build/src -lzoltan -lmpi -lm

• under mpi/intel64/lib/release path
• set export LIBRARY_PATH=$LIBRARY_PATH:/home/wpsze/intel/oneapi/mpi/2021.9.0/lib/release

Error 3

• /bin/sh: flex: command not found
• gcc: error: lex.yy.c: No such file or directory

The error message "flex: command not found" indicates that the flex program is not installed on your system or is not in your shell's search path. flex (Fast Lexical Analyzer) is a tool commonly used during the compilation of other software, such as the Linux kernel, to generate lexical analyzers.

• conda install conda-forge::flex
• For source env,
  • source intel first, and then conda env
    • source /home/wpsze/intel/oneapi/setvars.sh intel64
    • source /home/wpsze/micromamba/bin/activate cfd_env

Error 4

• undefined reference to '__gmpq_init' / '__gmpq_set'/ '__gmpn_copyi'

  • 1858 collect2: error: ld returned 1 exit status
    1859 make[2]: *** [/home/wpsze/openfoam/OpenFOAM-v2412/OpenFOAM-v2412/wmake/makefiles/general:174: /home/wpsze/openfoam/OpenFOAM-v2412/OpenFOAM-v2412/platforms/linux64GccDP     Int32Opt/bin/surfaceBooleanFeatures] Error 1
    1860 make[1]: *** [/home/wpsze/openfoam/OpenFOAM-v2412/OpenFOAM-v2412/wmake/makefiles/apps:28: surfaceBooleanFeatures] Error 2
    1861 make: *** [/home/wpsze/openfoam/OpenFOAM-v2412/OpenFOAM-v2412/wmake/makefiles/apps:28: surface] Error 2
    1862 make: *** Waiting for unfinished jobs....

    The error "undefined reference to __gmpq_init'" is a linker error in a C/C++ OpenFOAM project, indicating that the linker cannot find the implementation of the __gmpq_init function. This function belongs to the GNU Multiple Precision Arithmetic Library (GMP), which is often used as a dependency for other libraries like CGAL (CGAL（Computational Geometry Algorithms Library）是一個開源的 C++ 程式庫，提供高效且可靠的計算幾何演算法，涵蓋了多邊形、凸包、三角剖分、網格生成等各種幾何資料結構與演算法，廣泛應用於電腦輔助設計、地理資訊系統、電腦圖形、醫學影像、機器人學等領域，並採用雙授權模式 (LGPL/GPL 適用開源，商用需付費)。).

disucss

• ThirdParty clang without gmp/mpfr
  • If using ThirdParty clang without gmp/mpfr, the ThirdParty makeCGAL script will need to be run manually and specify that there is no gmp/mpfr.
  • Subequent compilation with Allwmake will now run largely without any problems, except that the components linking against CGAL (foamyMesh and surfaceBooleanFeatures) will also try to link against a nonexistent mpfr library. As a workaround, the link-dependency will be removed in wmake/rules/General/cgal by specifying the CGAL_FLAVOUR when compiling:

    • no-cgal | cgal-header | cgal-header-no-mpfr | cgal-no-mpfr | cgal-mpfr

  • A robuster solution is still being sought.

Common Solutions

• Explicitly link the library: Ensure that your project's Make/options file (if you are compiling within OpenFOAM's wmake environment) or your compiler command includes the linker flag for GMP.
  • Add -lgmp to the linker flags (e.g., LIBS variable in the options file). The order matters, and dependent libraries should typically appear after the libraries that use them in the linker command.
  • e.g. OpenFOAM-v2412/wmake/makefiles/general
    • EXE_LIBS = -lgmp, seems not works.
• Verify the library path: If GMP is installed in a non-standard location (e.g., in the OpenFOAM ThirdParty directory or a custom path), you need to specify the library directory using the -L flag and the include directory using the -I flag in your Make/options file.
  • LDFLAGS = -L$(GMP_LIB_PATH)
  • LIBS = -lgmp ...
• Check compatibility: Ensure that the architecture (32-bit vs. 64-bit) of your compiled code matches that of the GMP library you are linking against.
• Clean and rebuild: After making changes to your installation or options files, perform a clean build to ensure all object files and dependencies are correctly re-linked. Use wclean within your OpenFOAM project directory before running wmake again.