Can't build from source about ocamljava

[xclerc]

It looks like it fails when trying to link the first .jar file.
Could you try to use ocamljava.opt on an empty .ml
file to check whether this is indeed the problem?

[Vertmo]

Compiling an empty program does work without any issue. I think the problem may be coming from the patch applied to the ocamlbuild source before ocamlbuild is compiled (as it does touch the Options module), but I can't find how the original ocamlbuild source is downloaded.
When blocking said patch (by commenting out lines 30 and 46 in compiler/ocamlbuild/Makefile-ocamljava) the compilation of ocamlbuild works successfully, but the next step fails, as the unpatched version of ocamlbuild can't handle building .cmja targets.
Maybe the changes made to ocamlbuild since the last change to ocamljava have broken something ?

[xclerc]

Indeed, it looks like there is something broken with the
bootstrap of ocamlbuild. However, the problem should
not come from changes made to ocamlbuild since its
sources are vendored.

I wonder whether the problem could come from failing to
load Java elements. Which version of Java are you using?

[Vertmo]

I was trying with Java 8 (openjdk version "1.8.0_192"),
With Java 7 (openjdk version "1.7.0_171") the error is a bit different:

+ /home/vertmo/.opam/ocj2/bin/ocamljava.opt -c -annot -w L -w R -w Z -java-package ocaml.tools.ocamlbuild -for-pack Ocamlbuild_pack -o plugin.cmj plugin.ml               
File "plugin.ml", line 1:                                                                                                                                                 
Error: Java error:                                                                                                                                                        
unable to write data                                                                                                                                                      
Command exited with code 2.

It still happends during the ocamlbuild step tough.