I have the following CMakeLists.txt:

cmake_minimum_required(VERSION 3.20.0 FATAL_ERROR)

project(link_test)

add_library(my_lib1 SHARED my_lib1.c)
add_library(my_lib2 SHARED my_lib2.c)

target_link_libraries(my_lib2 PRIVATE my_lib1)

From the CMake docs I understand that target_link_libraries will create a dependency so that my_lib2 will be rebuilt if my_lib1.dll changes:

A library target name: The generated link line will have the full path
to the linkable library file associated with the target. The
buildsystem will have a dependency to re-link if the library
file changes.

However, if I delete my_lib1.dll and run cmake --build, I only see my_lib1.dll being built:

[1/2] Linking C shared library my_lib1.dll

Note the [1/2], as if there was a missing [2/2] step there.

On the other hand, if I delete my_lib1.lib (i.e. my_lib1‘s import library), then I do see the expected outcome:

[1/2] Linking C shared library my_lib1.dll
[2/2] Linking C shared library my_lib2.dll

Am I misunderstanding something here? Is the idea that the re-building of my_lib2.dll happens only when CMake detects that the symbols exported by my_lib1 may have changed (which would be reflected in my_lib1.lib)? If so, what’s the deal with that lone [1/2]?