The compiler provides an option for changing the directory for "temporary" files, --temp_directory, or -ft for short. This option does not function as its name suggests. It only applies to a subset of files that are of no use to end users, so it gives the appearance of having no effect. To globally change the directory where temporary files created by the compiler are placed, set the environment variable TMP before executing the compiler on Windows, or TMPDIR before executing the compiler on other host systems.