add_library() isn't aware of h-file location like add_executable()

[greenduck]

If I use add_executable() it automatically "knows" where to find every h-file.
However, add_library() with the same source files (except for main.cpp) requires adding target_include_directories() with the locations of all the h-files.
Shouldn't CPM find the h-files "for everyone" ?

[Radagan]

I'm having a similar problem with an executable using CPM 0.40.0 with our own libraries hosted on GitLab. Additionally, the libraries are not being built for some reason, so linking fails.

For example:

CPMAddPackage("gh:fmtlib/fmt#10.2.1")

...works fine, but this:

CPMAddPackage(
    NAME common
    VERSION 1.0.9
    GIT_REPOSITORY [email protected]
)

requires this to resolve the includes:

target_include_directories(myapp PUBLIC
    src
    $<BUILD_INTERFACE:${common_SOURCE_DIR}/include>
)