Adding new nightly versions

First, make sure the commit you want to add is fetch in the git tree at /your/rust/dir/.git. Then, import the right source files:

$ echo FULL_COMMIT_ID ...|GIT_DIR=/your/rust/dir/.git ./sync.sh

Instead of echoing in the commit IDs, you might pipe in rustc-commit-db list-valid.

Now look at the changes with git status. If nothing changed then the commit you tried to add was already there. If only mapping.rs changed, the I/O code has not changed for this particular commit. If a directory in src/ was added, cd into it to apply the patch.

Find out which previously-existing commit is closest to the new one and search this git repository for a commit with the description Patch COMMIT for core. For example, if you're adding dd56a6ad0845b76509c4f8967e8ca476471ab7e0, the best closest commit is 80d733385aa2ff150a5d6f83ecfe55afc7e19e68.

$ git log --pretty=oneline --grep=80d733385aa2ff150a5d6f83ecfe55afc7e19e68
92fc0ad81c432b5fa3e848fc1892815ca2f55100 Patch 80d733385aa2ff150a5d6f83ecfe55afc7e19e68 for core

The commit ID at the start of the line is the patch we'll try to apply:

$ git show 92fc0ad81c432b5fa3e848fc1892815ca2f55100|patch -p3
$ cargo build

Now, fix any errors cargo reports. If patch also reported errors, you may look at the rejects for inspiration ;).

Finally, commit this new version:

$ git commit -m "Patch dd56a6ad0845b76509c4f8967e8ca476471ab7e0 for core" .

Do not commit any files in different directories, this will break the patching scheme. If mapping.rs changed, update it in a separate commit.