Environment Variables

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 separately from MESA). If you haven’t moved it from the $MESA_DIR then set as GYRE_DIR=$MESA_DIR/build/gyre/src.

Optional#

MESA_CACHES_DIR#

Location where MESA will store and read cache files. See 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 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#

./build/bin/star can accept one argument that overrides the location of the inlist file. This will also override the environment variable $MESA_INLIST.

./build/bin/star some_other_inlist_file

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 and MESAROOT_SDK 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 turns on 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.

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