[cmake-developers] How to use cmake::SetCacheArgs(...)?

[Tobias Hunger]

Hello CMake developers,

I am trying to pass a number of arguments to cmake server-mode's
configure command. The exact call is:

[== "CMake Server" ==[
{
    "cacheArguments": [
        "-DCMAKE_BUILD_TYPE:STRING=Debug",
        "-DCMAKE_CXX_COMPILER:STRING=/usr/lib/ccache/bin/g++",
        "-DCMAKE_C_COMPILER:STRING=/usr/lib/ccache/bin/gcc",
        "-DCMAKE_PREFIX_PATH:STRING=/usr",
        "-DQT_QMAKE_EXECUTABLE:STRING=/usr/bin/qmake"
    ],
    "cookie": 2,
    "type": "configure"
}
]== "CMake Server" ==]

These are then fed into cmake::SetCacheArgs(...) by server-mode. That
call succeeds and I do see my values in the Cache once that is done
(via cmCacheManager::PrintCache(...)).

I then proceed to call cmake::Configure(...). That says something
about having to start over with a clean cache since the compiler
changed (which is correct).

After cmake::Configure(...) returns values some of the values are gone
again. E.g. CMAKE_BUILD_TYPE changed back from "Debug" to "".

Is this expected behavior?

When I resend the configure command to the cmake server all values stick.

Is that what I need to do? How do I know whether or not I need to
rerun configure again? Is there any telltale sign or at any
machine-readable notification that I need to send my data again? Or is
the procedure to just rerun configure with all arguments till the
cache no longer changes?

Best Regards,
Tobias