I have a node.js app that uses a native DLL built using MSVC and cmake-js. When compiled in release mode everything works great. However, I have some issues on the native side I need to debug, and am unable to get a debug build to work.

To build debug I’m using the following command:

cmake-js compile -B Debug --parallel && node custom_build.mjs

I then npm pack the debug binaries and npm install them in my node.js app. When I run the node.js app and try to use the methods exposed by the native DLL I get the following assertion:

Debug Assertion Failed! Expression: __acrt_first_block == header

I found a question from eight years ago about this but the only solution there was to build using /MDd, which I already am.

Any suggestions for how to track down where the error is? It appears to be some sort of mismatch between the native DLL and node.js builds, but I’m at a loss for how to proceed.