===================== Environment Variables ===================== The following lists environment variables that can affect the way MESA runs. Essential --------- MESA_DIR ~~~~~~~~ Location of the MESA source code. GYRE_DIR ~~~~~~~~ Location of the GYRE source code (only needed if running GYRE). If you haven't moved it from the ``$MESA_DIR`` then set as ``GYRE_DIR=$MESA_DIR/gyre/gyre``. Recommended ----------- OMP_NUM_THREADS ~~~~~~~~~~~~~~~ Number of threads MESA will run with. Should be between 1 and 2 * number of logical cores. MESASDK_ROOT ~~~~~~~~~~~~ Location of the SDK. Optional -------- MESA_CACHES_DIR ~~~~~~~~~~~~~~~ Location where MESA will store and read cache files. See :ref:`star_job.defaults cache directories ` for more details. Beware when using this and changing MESA versions; best practice would be to remove its contents upon changing versions. MESA_TEMP_CACHES_DIR ~~~~~~~~~~~~~~~~~~~~ Location where MESA will write the cache file temporarily before moving to ``$MESA_CACHES_DIR``. If set, this folder MUST be unique for each MESA run. If not set defaults to ``./.mesa_temp_cache``. MESA_OP_MONO_DATA_PATH ~~~~~~~~~~~~~~~~~~~~~~ Location of the OP_MONO data files. See the :ref:`radiative levitation ` test suite (located in ``$MESA_DIR/star/test_suite/radiative_levitation/inlist_radiative_levitation``) for more details. MESA_INLIST ~~~~~~~~~~~ By default MESA will look for a file called ``inlist`` in the local working directory for its configuration. This overrides the filename and can point to a file somewhere else. MESA_FORCE_PGSTAR_FLAG ~~~~~~~~~~~~~~~~~~~~~~ If set, this shell variable will override the inlist variable ``pgstar_flag``. If set to either ``true`` or ``TRUE`` MESA will act as if the user had set ``pgstar_flag=.true.`` in their inlist. If set to either ``false`` or ``FALSE`` MESA will act as if the user had set ``pgstar_flag=.false.`` in their inlist. If set to anything else (or not set at all) MESA will use the value as set in the inlists. MESA_SKIP_OPTIONAL ~~~~~~~~~~~~~~~~~~ If set then when running a test_suite case, then certain optional inlists will be skipped. If not set, then all inlists will be run. Misc ---- Useful things that are not environment variables. Command line arguments ~~~~~~~~~~~~~~~~~~~~~~ ``./star`` can accept one argument that overrides the location of the inlist file. This will also override the environment variable ``$MESA_INLIST``. :: ./star some_other_inlist_file skip_build ~~~~~~~~~~ Empty file. If present in ``$MESA_DIR`` then no compiling is done when ``./install`` is invoked. If present in a sub folder (e.g ``$MESA_DIR/eos``) then no compiling is done in the sub-folder. skip_test ~~~~~~~~~ Empty file. Similar to ``skip_build``, but this will skip the compile time tests. If placed in a sub-folder, then only the tests in that folder are skipped. Private ------- These options are for developers; you do not need them for normal usage. If you use them and things break then stop using them. MESA_DIR_INTENTIONALLY_EMPTY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Bypass checks done at compile time for checking if ``$MESA_DIR`` is set. MESA_TEMP_CACHES_DISABLE ~~~~~~~~~~~~~~~~~~~~~~~~ If set, then we do not use the temp cache mechanism, writing cache files directly to the ``$MESA_DIR/data/`` folder. MESA_ERROR_BACKTRACE_DISABLE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If set, disables the generation of backtraces when we call ``mesa_error()``. This is mostly helpful on macs, as they don't generate useful backtraces. MESA_FPE_CHECKS_ON ~~~~~~~~~~~~~~~~~~ When set to 1 this will turn on a series of compile time checks as well as certain inlist options designed to catch floating point exceptions. This should not be set during a normal run. MESA_TEST_SUITE_RESOLUTION_FACTOR ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If set to a value other than 1, then ``mesh_delta_coeff`` and ``time_delta_coeff`` will be multiplied by its value, and ``max_model_number`` will be multiplied by its inverse. For example, this can be set to 0.5 to double the space and time resolution as well as the maximum model number. During a normal run, this should be either set to 1, or not set.