`npm run build` error on the Ubuntu 19.04

I've tried building the [example-flow-field](https://github.com/ekosz/reprocessing-example-flow-field example) and I got this error:
```
> reprocessing-example@ build /home/tomasz/Desktop/projects/cp-flow
> bsb -make-world

ninja: no work to do.
[1/1] Building run_build_script
FAILED: run_build_script
/home/tomasz/Desktop/projects/cp-flow/node_modules/Tsdl/lib/bs/bytecode/build_script.exe /home/tomasz/Desktop/projects/cp-flow/node_modules/bs-platform/vendor /home/tomasz/Desktop/projects/cp-flow/node_modules/bs-platform/vendor/ocaml/lib/ocaml /home/tomasz/Desktop/projects/cp-flow/node_modules/Tsdl /home/tomasz/Desktop/projects/cp-flow
Fatal error: cannot load shared library dllunix
Reason: /home/tomasz/.opam/default/lib/ocaml/stublibs/dllunix.so: undefined symbol: caml_ba_element_size
ninja: error: rebuilding 'build.ninja': subcommand failed
Failure: /home/tomasz/Desktop/projects/cp-flow/node_modules/bs-platform/lib/ninja.exe
Location: /home/tomasz/Desktop/projects/cp-flow/node_modules/Tsdl/lib/bs/bytecode
```

I'd gone through other issues, such as #8 but I still couldn't solve it.