Linux building process is cumbersome and poorly documented

[throwable-one]

It says

running make in the root directory of the capnproto-java repository should build capnpc-java.

but Makefile has: CAPNP_CXX_FLAGS=-I $(CAPNP_PREFIX)/include -L $(CAPNP_PREFIX)/lib -lkj -lcapnp

There is no include dir in capnproto: there is capnp: https://github.com/capnproto/capnproto/tree/v2/c%2B%2B/src
One could build it with

make CAPNP_CXX_FLAGS="-I path_to_src -L path_to_libs -lkj -lcapnp  -o capnpc-java"

but this is not very obvious.

And even this command builds dynamic executable (unlike capnpc itself which is static) which is not very convenient.

I wish we had something like

PATH_TO_CAPNP_SRC=../some/path make