Help with target_precompile_headers

Code
1

Problem, Windows10, vs2019: using

target_precompile_headers(some_target PRIVATE _pch.h)

when building a subcomponent of a static library, some.lib. The problem is that when I try to link to some.lib, I get a LNK2011: precompiled header not linked in, naming a seemingly random file from the directory of some_target. (Gotta love Windows).
I have a file in the target called _pch.cpp that includes _pch.h, whiich was the way I used it with Cotire.
However, I don’t think _pch.cpp.obj is the precompiled header object, as it is only 3kb. It seems to be some_target/CMakeFiles/some_target.dir/CMakeFiles/some_target.dir/cmake_pch.cxx.obj

So, if I put a

target_sources(some_target CMakeFiles/some_target.dir/cmake_pch.cxx)

this problem is rectified.

However, this approach sounds counter intuitive to me. It seems like this inclusion should happen automatically, at least on Windows with Ninja.
NOTE: On Linux there is no problem.

2

Actually, this approach does not work, since ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/some_target.dir/cmake_pch.cxx will not exist at the time of CMake configuration.

3

The issue is that most of my static library subsections are OBJECT libraries.
In directory lib1:

add_library(lib1 OBJECT ...)
target_precompile_headers(lib1 PRIVATE _pch.h)

In directory lib2:

add_library(lib2 OBJECT ...)
target_precompile_headers(lib2 PRIVATE _pch.h)

In superior directory:

add_subdirectory(lib1)
add_subdirectory(lib2)
add_library(some_lib STATIC ...)
target_link_libraries(some_lib PRIVATE lib1 lib2)

This generated some_lib.lib and installed it in a suitable place to where it could be linked.
In another separate project:

add_library(thing SHARED ...)
target_link_libraries(thing PRIVATE some_lib)

I would get

LNK2011: (.../somelib1file.cpp) precompiled header not linked in, image may not run
LNK2011: (.../somelib2file.cpp) precompiled header not linked in, image may not run

However, I discovered that if I just made ONE of those subdirectory precompiled headers PUBLIC the shared library would link to it.

So, my solution was to generate a bogus/empty precompiled header for the STATIC library, and that seemed to rectify the problem.

add_subdirectory(lib1)
add_subdirectory(lib2)
add_library(some_lib STATIC ...)
target_precompiled_header(some_lib PRIVATE bogus.h)
target_link_libraries(some_lib PRIVATE lib1 lib2)

Something about this discovery just doesn’t seem right.
I have not yet gotten to the point of testing this approach, just yet.