CPack NSIS component is Unspecified

Behold the following fairly trivial CMake file:

cmake_minimum_required(VERSION 3.7)

add_library(libdice SHARED lib.cpp)

set_target_properties(libdice PROPERTIES
    PREFIX ""
    OUTPUT_NAME "Dice"
    PUBLIC_HEADER "lib.h"
)

install(TARGETS libdice
    RUNTIME DESTINATION "lib"
    LIBRARY DESTINATION "lib"
    PUBLIC_HEADER DESTINATION "include"
    COMPONENT sdk
)

set(CPACK_PACKAGE_NAME "Dice SDK")
set(CPACK_GENERATOR "NSIS")

include(CPack)

cpack_add_component(sdk)

With this lib.h:

#pragma once

int sides_of_a_dice();

And lib.cpp:

int sides_of_a_dice()
{
    return 6;
}

So if I nmake package for this on Windows it for some reason puts Dice.dll in an Unspecified component, even thought the component is clearly specified. Even weirder, the public headers (lib.h) correctly go in the sdk component.

CPack: Create package using NSIS
CPack: Install projects
CPack: - Run preinstall target for: Project
CPack: - Install project: Project
CPack: -   Install component: Unspecified   <- Why??!
CPack: -   Install component: sdk
CPack: Create package

What is going on?

Solution

According to documentation for install command, every specification of file's type (like RUNTIME, LIBRARY or PUBLIC_HEADER) starts its own install clause, to which all other options are applied.

That is, option COMPONENT sdk is applied only to file's type PUBLIC_HEADER.

Other files (RUNTIME, LIBRARY) have component option unspecified.