- 1 General
- 2 Usage
- 2.1 How do I build GEOS-Chem with CMake?
- 2.2 How do I make clean?
- 2.3 How do I change GEOS-Chem's build options?
- 2.4 I got a CMake error. How do I fix it?
- 3 Advanced
- 4 Further reading
What is CMake?
CMake is a program that generates Makefiles. This is an oversimplification, but it describes the essence of CMake.
What versions of GEOS-Chem support CMake?
GEOS-Chem Classic 12.6.0 and later support CMake.
GCHP supports CMake starting in version 13.0.0.
How do I build GEOS-Chem with CMake?
cd <run directory> # 1. Go to your run directory mkdir build # 2. Create a build directory cd build # 3. cd into your build directory cmake <path to GEOS-Chem's source code> # 4. Configure GEOS-Chem's build make -j # 5. Compile GEOS-Chem make install # 6. Install the geos executable in your run directory
See Building GEOS-Chem with CMake more details.
Can I build GEOS-Chem Classic and GCHP in the same environment?
Yes. Because GEOS-Chem Classic's requirements are a subset of GCHP's.
How do I build specific targets?
Pass the target's name as an argument to
make. You can build multiple specific targets by passing multiple names.
How do I
You don't need to do this anymore. Now, when you run
make, the build system automatically figures out what needs to be recompiled. A "
clean" target still exists, but it cleans everything.
If you want to restart the build from scratch, you can do
How do I continue a build that was terminated before it finished?
make command again. The build system will automatically pick up where it left off.
How do I recompile after I make modifications to the source code?
The build system will automatically figure out what needs to be recompiled when you run
make. There is no need to run "cleaning" commands.
How do I clean my build's configuration (i.e. CMake's files)?
Just delete your build directory, and remake it.
rm -rf build mkdir build cd build
When should I delete my build directory (i.e. clean my build's configuration)?
You build directory holds information about your build environment—things like which compilers you are using and the paths to dependencies like NetCDF. Because of this, you should create a new build directory whenever your environment changes. Don't hesitate to delete your build directory—they are easy to remake.
How do I change GEOS-Chem's build options?
Build options set through CMake variables. You can set CMake variables with
-D<name>="<value>" arguments. Note that "ON", "OFF", "TRUE", "FALSE", etc. are valid booleans in CMake.
cmake . -DFOO="BAR" # set's the variable FOO equal to "BAR"
How do I disable multithreading (i.e. OpenMP)?
cmake . -DOMP=OFF
How do I disable colorized output?
cmake . -DCMAKE_COLOR_MAKEFILE=FALSE
How do I increase the build's verbosity?
cmake . -DCMAKE_VERBOSE_MAKEFILE=TRUE
How do I build for debugging?
cmake . -DCMAKE_BUILD_TYPE=Debug
How do I build with custom compiler flags?
You can specify custom compiler flags with the
CMAKE_Fortran_FLAGS variable. These will be added to the list of compiler flags that GEOS-Chem is compiler with.
cmake . -DCMAKE_Fortran_FLAGS="-march=skylake"
I got a CMake error. How do I fix it?
CMake can't find NetCDF. How do I fix this?
If CMake is not finding NetCDF and NetCDF-Fortran on your machine it will print the following error message.
CMake Error at /usr/share/cmake-3.5/Modules/FindPackageHandleStandardArgs.cmake:148 (message): NETCDF_F_LIBRARY: Path to "libnetcdff.so" NETCDF_C_LIBRARY: Path to "libnetcdf.so" NETCDF_C_INCLUDE_DIR: Directory containing "netcdf.h" NETCDF_F90_INCLUDE_DIR: Directory containing "netcdf.mod" NETCDF_F77_INCLUDE_DIR: Directory containing "netcdf.inc" Find the directories/files that are listed above. Specify the directories you want CMake to search with the CMAKE_PREFIX_PATH variable (or the NetCDF_ROOT environment variable). (missing: NETCDF_F_LIBRARY NETCDF_C_LIBRARY NETCDF_C_INCLUDE_DIR NETCDF_F90_INCLUDE_DIR NETCDF_F77_INCLUDE_DIR) Call Stack (most recent call first): /usr/share/cmake-3.5/Modules/FindPackageHandleStandardArgs.cmake:388 (_FPHSA_FAILURE_MESSAGE) CMakeScripts/FindNetCDF.cmake:138 (find_package_handle_standard_args) CMakeLists.txt:44 (find_package) -- Configuring incomplete, errors occurred! See also "/stetson-home/bindle/geos-chem/build/CMakeFiles/CMakeOutput.log".
To resolve this, you need to point CMake to where NetCDF and NetCDF-Fortran are installed. This can be done by setting environment variables
NetCDF_Fortran to the directory/directories where NetCDF is installed. The directory/directories where NetCDF is installed should have subdirectories like
Can I build GEOS-Chem without a run directory?
Yes. Initialize your build directory with the following command
cmake -DRUNDIR=IGNORE -DRUNDIR_SIM=standard /path/to/your/source/code
Can I use Ninja rather than GNU Make?
Yes. You'll need CMake version 3.7 or greater and Kitware's Ninja distribution (for Fortran futures). To use the Ninja generator rather than the Makefile generator, initialize your build directory with
cmake -GNinja <path to source code>.
Are the environment variables like
No, these are just for convenience. You can configure the build with the standard
CMAKE_PREFIX_PATH variables, rather than environment variables, if you'd prefer. This means GEOS-Chem doesn't impose environment variable requirements on superprojects.
How do I build GEOS-Chem as a part of an other project?
Currently, this is an undocumented feature (see: https://github.com/geoschem/geos-chem/issues/195).
- Compiling with CMake section of Getting Started with GEOS-Chem
- CMake tutorial (cmake.org)
- Learn X in Y minutes (where X is CMake)