Mundane is maintained in its own repository. Backporting from the upstream repository into Fuchsia is done manually. To backport, follow these steps:
Checkout the master branch from the upstream and ensure it is passing tests via cargo test --all-features.
Change the copyright headers in source files from the Google copyright to the Fuchsia copyright. This can be done using a file containing the Fuchsia license via fd (or find) and sed from the repository root:
fd . src/ -e rs -x sed -i '1,5d' {} fd . src/ -e rs -x sed -i -e '1rfuchsia-license.txt' -e '1{h;d}' -e '2{x;G}' {}
Be mindful of files that may be missing the Google copyright in the upstream repository; the above use of sed blindly removes the first five lines of every file found by fd.
Replace the boringssl::ffi module with boringssl_sys. This requires an extern crate boringssl_sys import in lib.rs and that references to boringssl::ffi are replaced with boringssl_sys. For unqualified references to the ffi module, it should be possible to create a binding via use boringssl_sys as ffi.
Copy the src directory from the edited upstream into a Fuchsia checkout at src/lib/mundane.
Format the code via fx format-code.
Note that it may be necessary to integrate with changes submitted to the Fuchsia repository but not upstream. See previous backport commits for some examples.
See the diffs in 0001-Mundane-backport.patch.