Haxe ubuntu installation issue


I’ve been trying to install Haxe 4.0.0 preview2 (not the latest preview4). I’ve cloned the branch https://github.com/HaxeFoundation/haxe/tree/development-4.0.0-preview.2 and followed the installation steps:

1, Install Neko, which is available in the repositories of many Linux distributions. e.g. On Ubuntu, just sudo apt-get install neko.
2. Install OCaml (4.02 or above), camlp4, pcre, and zlib. Again, try to find such packages in the Linux repositories.
3. Navigate to where the Haxe sources are and build Haxe using make:
make install

The installation returns the following error:

make -C libs/extlib-leftovers native && make -C libs/extc native && make -C libs/neko native && make -C libs/javalib native && make -C libs/swflib native && make -C libs/ttflib native && make -C libs/ilib native && make -C libs/objsize native && make -C libs/pcre native && make -C libs/ziplib native && true
make[1]: Entering directory ‘/home/haxe_make/libs/extlib-leftovers’
make[1]: Nothing to be done for ‘native’.
make[1]: Leaving directory ‘/home/haxe_make/libs/extlib-leftovers’
make[1]: Entering directory ‘/home/haxe_make/libs/extc’
ocamlfind ocamlopt -safe-string -a -o extc.cmxa -package extlib extc.ml process.ml
File “extc.ml”, line 144, characters 10-18:
Error: Unbound module IO
Makefile:16: recipe for target ‘extc.cmxa’ failed
make[1]: *** [extc.cmxa] Error 2
make[1]: Leaving directory ‘/home/haxe_make/libs/extc’
Makefile:112: recipe for target ‘libs’ failed
make: *** [libs] Error 2

Please help me resolve the installation issue.

Did you clone all submodules?