reuse_compile_from is a heavily used function part of DSI. It is quite sensitive to outside forces (such as the main mongo compile) and it is not tested in either the standard patch test, or the DSI commit queue.

We should add a check for reuse_compile_from against the main versions of MongoDB, including master, in the commit queue. We will either notice when it is broken underneath us by PRs failing, guaranteeing prompt action, or we will notice when we have broken it.

See here for an example of the frustration this can cause.