[AkulRanjan]

I have fixed #1655 by using CMake's existing CMAKE_MSVC_RUNTIME_LIBRARY setting instead of introducing a new project-specific option. This requires CMake 3.15 or later for deployment.

The MSVC CI job now tests both /MD and /MT configurations. The /MT configuration is restricted to static libraries, since using the static runtime with shared libraries can cause separate DLLs to manage their own runtime heaps. I also encountered __acrt_first_block == header debug assertion failures when testing the shared library and /MT combination locally.

The CI matrix increases from 8 to 12 jobs, with .MD and .MT added to job names to make the runtime configuration explicit.

Testing

I tested locally on Visual Studio 2022 (MSVC 19.44) with CMake 4.4.4 and all six targets use the static runtime in the /MT configuration. The test executable runs without requiring the MSVC runtime DLLs and all 87 tests pass.
However, I have not tested locally on Visual Studio 2026.

AI disclosure

I used an AI coding assistant to help investigate the CMake configuration and work through the implementation. I guided it humanly to execute the changes and I reviewed the resulting changes and tested the static-runtime configuration locally.

[dmah42]

do we need this line? do we say elsewhere in the docs to add /MT? if so maybe just remove that advice.

[AkulRanjan]

Right, the docs don't actually mention adding /MT, so I removed that part to keep things accurate.

I nonetheless kept the note about limiting /MT to static libraries, since I ran into cross-CRT heap assertion failures when testing it with shared libraries locally.

[dmah42]

our branch protection will need updating right after we merge. i'll update it after force merging this.