rebar compile fails with bitcask - "errno.h": no such file - compilation

Question

I am new to Erlang, so i am going through Joe Armstrong's book "Programming Erlang". In chapter 25 there's an example on how to work with rebar. I followed the instructions and created a Makefile
all:
test -d deps || rebar get-deps
rebar compile -v
#erl -noshell -pa './deps/bitcask/ebin' -pa './ebin' -s myapp start
and rebar.config
{deps, [
{bitcask, ".*", {git, "git://github.com/basho/bitcask.git", "master"}}
]}.
Getting the dependencies works, but compiling fails.
The verbose output tells me that this command fails
cmd: cc -c $CFLAGS -g -Wall -fPIC -I"/usr/lib/erlang/lib/erl_interface-3.7.18/include" -I"/usr/lib/erlang/erts-6.2/include" c_src/bitcask_nifs.c -o c_src/bitcask_nifs.o
with this error
/home/user/folder/deps/bitcask/c_src/bitcask_nifs.c:22:19: fatal error: errno.h: No such file or directory
But
find /usr/include -name errno.h
gives me
/usr/include/x86_64-linux-gnu/asm/errno.h
/usr/include/asm/errno.h
/usr/include/linux/errno.h
/usr/include/asm-generic/errno.h
So I was asking myself..
what am I missing?
how can I tell rebar about the depencies on the C libraries and where to find them?
why isn't this configured correctly in the Makefile of bitcask?
Maybe I was searching for the wrong terms, but I couldn't find any solution in the internets.
Many thanks in advance

Answer 1

There are two thing to consider
rebar options
You can set options for compiling C code with port_env option in rebar.config.
comiling deps
Since bitstack is your dependency, it is not compiled with yours rebar config, but with it's own. So if you would like to change anything, you would have to modify the bitcask file.
Fortunately, if you look into config their writen all C compilation is done with environment variable $ERL_CFLAGS. And again, in rebar source code you can see that this flag is responsible for include paths in your compilation.
So easist way would be extending $ERL_CFLAGS in your Makefile before compilation, with something like this
all: ERL_CFLAGS = "$ERL_CFLAGS -I /usr/include/linux/errno.h"
all:
test -d deps || rebar get-deps
rebar compile -v
#erl -noshell -pa './deps/bitcask/ebin' -pa './ebin' -s myapp start
Just make sure that this include works for you, and that you are not overwriting any flags you are using.