ocamlbuild (1) - Linux Man Pages

ocamlbuild: The OCaml project compilation tool


ocamlbuild - The OCaml project compilation tool


ocamlbuild [ -Is  dir1,... ] [ -libs lib1,... ] [ -lflags flag1,... ] [ -pp flags ] [ -tags tag1,... ] [ -j  parallel-jobs ] target.native [ -- arg1 arg2 ... ]

(same options)


ocamlbuild(1) orchestrates the compilation process of your OCaml project. It is similar in function to make(1) except that it is tailor-made to automatically compile most OCaml projects with very little user input.

ocamlbuild should be invoked in the root of a clean project tree (e.g., with no leftover compilation files). Given one or more targets to compile, it scans the required subdirectories to gather information about the various files present, running tools such as ocamldep(1) to extract dependency information, and gathering optional files that fine-tune its behaviour. Target names are very significant.


ocamlbuild uses a set of target naming conventions to select the kind of objects to produce. Target names are of the form base.extension where base is usually the name of the underlying OCaml module and extension denotes the kind of object to produce from that file -- a byte code executable, a native executable, documentation... Of course extensions such as .cmo, .cma, .cmi... map to their usual counterparts. Here is a list of the most important ocamlbuild-specific extensions:

Native code executable

Byte code executable

Interface inferred with ocamlc-i

HTML documentation generated with ocamldoc


The following command-line options are recognized by ocamlbuild(1).

Display the version
Make as quiet as possible
-verbose <level>
Set the verbose level
Show rules and flags
-log <file>
Set log file
No log file
Remove build directory and other files, then exit
-I <path>
Add to include directories
-Is <path,...>
(same as above, but accepts a comma-separated list)
-X <path>
Directory to ignore
-Xs <path,...>
-lib <flag>
Link to this ocaml library
-libs <flag,...>
-lflag <flag>
Add to ocamlc link flags
-lflags <flag,...>
-cflag <flag>
Add to ocamlc compile flags
-cflags <flag,...>
-yaccflag <flag>
Add to ocamlyacc flags
-yaccflags <flag,...>
-lexflag <flag>
Add to ocamllex flags
-lexflags <flag,...>
-ppflag <flag>
Add to ocaml preprocessing flags
-pp <flag,...>
-tag <tag>
Add to default tags
-tags <tag,...>
-ignore <module,...>
Don't try to build these modules
Don't make links of produced final targets
Don't skip modules that are requested by ocamldep but cannot be built
Don't apply sanity-check rules
Don't build myocamlbuild.ml
Don't ignore stdlib modules
Just build myocamlbuild.ml
Don't use a native plugin but bytecode
Do not enforce sanity-check rules
Fail if something needs to be rebuilt
Display executed commands the old-fashioned way
-j <N>
Allow N jobs at once (0 for unlimited)
-build-dir <path>
Set build directory
-install-dir <path>
Set the install directory
Display the install directory
-ocamlc <command>
Set the OCaml bytecode compiler
-ocamlopt <command>
Set the OCaml native compiler
-ocamldep <command>
Set the OCaml dependency tool
-ocamlyacc <command>
Set the ocamlyacc tool
-ocamllex <command>
Set the ocamllex tool
-ocamlrun <command>
Set the ocamlrun tool
Stop argument processing, remaining arguments are given to the user program
Display the list of options
Display the list of options


The ocamlbuild manual, ocaml(1), make(1).
The OCaml user's manual, chapter Batch compilation.