Why can't nasm find include statements from cmake

Question

I have a modular boot loader i'm toying with. I felt it would be more of a pain setting it up to use gas than to port nasm to cmake. It seems not to be that way. NAsm is unable to find the include file. What am I missing?

The entire code can be found in This Github Repo

Here is the project layout:

.
├── CMakeLists.txt
└── Failing_module
    ├── CMakeLists.txt
    ├── Print.inc
    └── Stage1
        └── Stage1.asm

./CMakeLists.txt:

cmake_minimum_required(VERSION 3.6)
project(fails C ASM_NASM)
add_subdirectory(Failing_module)

Failing_module/CMakeLists.txt:

enable_language(ASM_NASM)
set(CMAKE_ASM_NASM_OBJECT_FORMAT bin)

set(module_SRCS Stage1/Stage1.asm)

set(CMAKE_NASM_LINK_EXECUTABLE nasm)
add_executable(Stage1.bin ${module_SRCS})
set_target_properties(Stage1.bin PROPERTIES LINKER_LANGUAGE NASM)
install(TARGETS Stage1.bin DESTINATION bin)

Failing_module/Stage1/Stage1.asm:

bits 16

jmp main

%include "Print.inc"
msgHello db "Hello World", 0x00

main:
    mov s, msgHello
    call Print

Failing_module/Print.inc

Print:
    lodsb
    or  al, al
    jz  PrintDone
    mov ah, 0x0E
    int 0x10
    jmp Print
PrintDone:
    ret

The output of cmake is the following:

Failing_module/Stage1/Stage1.asm:6: fatal: unable to open include file `Print.inc'
make[2]: *** [Failing_module/CMakeFiles/Stage1.bin.dir/build.make:63:  Failing_module/CMakeFiles/Stage1.bin.dir/Stage1/Stage1.asm.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:86: Failing_module/CMakeFiles/Stage1.bin.dir/all] Error 2
make: *** [Makefile:128: all] Error 2

EDIT Should compile by manual means now. This makes it a SSCCE

Answer 1

I believe the problem here is that some strictness in CMake interacts poorly with a flaw in NASM. CMake insists that search paths (such as %include paths) do not have a trailing slash. nasm insists that search paths (given with a -I option) do have a trailing slash. CMake won't be changed; its developers do not regard this as a CMake bug. They are right: nasm should not insist that include paths have a trailing slash. The nasm fault has been known for several years.

I managed to work around this issue by hiding the search path as a normal compile option:

 add_compile_options(-I ${CMAKE_CURRENT_SOURCE_DIR}/ )
 add_library( my_lib STATIC "my_source.asm" )