dune:tldr:d4d8a

The command "dune build" is used in dune (formerly known as jbuilder), a build system for OCaml projects. This command is used to build the project by compiling the source code, linking dependencies, and generating the executable files or libraries specified in the project configuration.

When you run "dune build" in the terminal, it reads the dune files (dune and dune-project) in the project directory to determine the build configuration. These files specify the source files, dependencies, build rules, and other project-specific settings.

The "dune build" command then analyzes the dependencies and determines the necessary build steps. It compiles the OCaml source files (.ml, .mli) into object files (.cmo, .cmi) and then links them together to create the desired executable or library.

The output of the "dune build" command is usually placed in a _build directory within the project directory. The exact location and structure of the output files can be configured using the dune files.

By using "dune build", you ensure that your project is correctly compiled and built according to the defined rules and dependencies, providing a reliable and reproducible way to build your OCaml project.