The include statements presented here corresponds to the values of RbConfig::CONFIG["rubylibdir"] and RbConfig::CONFIG["rubyarchdir"]', so I thought using rbconfig to setup the compilation will give me much better results when compiling on different platforms. I wrote the following Makefile with the prior in mind:

librb    = $(shell ruby -e 'puts RbConfig::CONFIG["rubylibdir"]')
arch_dir = $(shell ruby -e 'puts RbConfig::CONFIG["rubyarchdir"]')

CC      := gcc -std=c99
EXEC    := test
SRCS    := src/[a-z]*.c
LIBS    := -I$(librb) -I$(arch_dir) -lruby
CFLAGS  := -g -Wall -Wextra -Woverflow -Og -pedantic

$(EXEC): $(SRCS)
        $(CC) -o $@ $^ $(CFLAGS) $(LIBS)

Which on my system results in:

gcc -std=c99 -o object_test src/main.c -g -Wall -Wextra -Woverflow -Og -I/home/user/.rbenv/versions/3.2.2/lib/ruby/3.2.0 -I/home/user/.rbenv/versions/3.2.2/lib/ruby/3.2.0/x86_64-linux -lruby

For some reason I still get, “ruby.h: No such file or directory” fatal error, when trying to compile the following code.

#include <ruby.h>

int main(int argc, char* argv[])
{
  ruby_init();
  //...
  return ruby_cleanup(0);
}

I know that my question may seem a duplicate of this one, but the links are broken there and it’s outdated by 13 years. I am most concerned about ruby > 3.1 for my project.