We are in Programmer Hell

We have a ourlibrary.a file built in March

We can link ourlibrary.a into an application, it builds and the program runs

But if we build ourlibrary.a from source, the same untouched code and vcxprojes from march, it produces an ourlibrary.a that— when linked into the application— causes the final application to fail with a linker error that it can't find any of the OpenGL symbols.

Something changed on *the build machine* since March and we don't know what.