@mcc you may be able to use workspaces to block it (see link),
or by explicitly overriding the values messing things up in the submodules config file.

https://users.rust-lang.org/t/how-to-override-cargo-config-search-order/38197/4

@mcc my understanding is the workspace would be defined in the submodule, so that when you call cargo *in that submodule*, it will only read submodule/.cargo/config.toml

similarly, submodule/.cargo/config.toml values take precedence over root/.cargo/config.toml
so if it were:

root/.cargo/config.toml::[build] jobs = 2

that was breaking things, you would override with:

root/submodule/.cargo/config.toml::[build] jobs = 1