spectral

A monolithic kernel work wrapper, to make it easy.

Status: scaffold. The command surface parses, every verb is wired through main to its module, and the paths resolve — but the bodies are todo!(). Twenty of them. Nothing builds a kernel, boots qemu, scrapes bugzilla, or sends mail yet. What exists is the shape of the thing and the seams to fill in, which is exactly what the Where to pitch in section below is for.

Why

The kernel patch lifecycle is a dozen commands you retype every time. Find something to fix, write it, run checkpatch, run it again after --fix, commit with the right trailer, build, boot it under qemu, diff against master, work out who the maintainers are for those files, send. Then a week later do it all again as v2, remembering to thread it off the original.

None of those steps are hard. They are just easy to get subtly wrong, and the subtle mistakes — a missing Signed-off-by, a v2 that doesn't thread, a missing CC — are the ones that get a patch ignored rather than reviewed.

spectral is a thin wrapper over that loop. It is deliberately thin: every verb shells out to a tool you already have and already trust.

What it wraps

Nothing here reimplements kernel tooling, and nothing vendors it:

spectral	actually runs
patch check / patch format	scripts/checkpatch.pl from your tree
patch commit	git commit
patch create	git diff <base>
patch submit	scripts/get_maintainer.pl from your tree, then git send-email
kernel test	make, then qemu-system-x86_64
kernel quest	HTTP against bugzilla.kernel.org

The two scripts are called out because it matters: they come from the tree you are working in, so spectral cannot have a stale copy of the kernel's own style rules or maintainer map. Upgrade your tree, get the new rules.

And because it is thin, you can always drop the wrapper. patch submit --dry-run prints the recipients and the exact git send-email command line instead of sending, so you can check the plumbing or just run it yourself.

The loop

What the finished tool should feel like — none of this runs yet:

$ spectral kernel quest
12345 usb: xhci: device does not enumerate after resume
https://bugzilla.kernel.org/show_bug.cgi?id=12345

# ... go and fix it, in the tree ...

$ spectral patch check
$ spectral patch format          # checkpatch --fix, then check again
$ spectral patch commit "usb: xhci: re-arm the port after resume" --signoff
$ spectral kernel test           # build, then boot it under qemu
$ spectral patch create 000-xhci-port-rearm
~/.spectral/patches/000-xhci-port-rearm.patch

$ spectral patch submit 000-xhci-port-rearm.patch --dry-run
# happy? drop --dry-run and it goes out

# ... wait for review ...

$ spectral patch update 000-xhci-port-rearm.patch -v 2
~/.spectral/patches/v2-000-xhci-port-rearm.patch
$ spectral patch submit v2-000-xhci-port-rearm.patch --in-reply-to '<msg-id-of-v1>'

One deviation from the obvious design: patch update is a single subcommand taking -v N rather than a generated update-v2 / update-v3. clap subcommands are static, and a flag beats a subcommand you cannot tab-complete. Leave -v off and it infers the next revision from the file's current vN- prefix.

Install

Needs a recent stable Rust — edition 2024, so 1.85 or newer; developed against 1.98.1.

$ git clone https://git.spectoria.dev/huntedbytheirs/spectral.git
$ cd spectral
$ cargo build --release
$ install -Dm755 target/release/spectral ~/.local/bin/spectral

Not on crates.io, so cargo install spectral will get you something else. cargo install --path . from a clone works too.

Beyond Rust you want:

• a kernel tree — for scripts/checkpatch.pl and scripts/get_maintainer.pl. Both ship with the kernel; spectral does not carry its own.
• git with send-email configured — git send-email must work from a plain shell first. If it does not, patch submit cannot make it work, and is not meant to.
• qemu — qemu-system-x86_64 on $PATH, for kernel test.

Configuration

There is no config file yet. Two paths matter, and both come from the environment with $HOME-relative defaults:

what	resolution
kernel tree	$SPECTRAL_KERNEL, else ~/.spectral/linux
patch dir	~/.spectral/patches

$ export SPECTRAL_KERNEL=$HOME/src/linux

A tree is accepted only if it has scripts/checkpatch.pl; otherwise you get not a kernel source tree rather than a confusing failure three steps later. A missing tree reports the path and the variable that would have set it. The tree is not required for kernel quest, which only needs the network.

~/.config/spectral/config.toml and a spectral init to clone the tree are planned, not built — src/config.rs is the only file that will have to change for either.

Commands

$ spectral --help
A monolithic kernel work wrapper to make it easy.

Usage: spectral <COMMAND>

Commands:
  kernel  Find work, build it, boot it
  patch   Carry a change from working tree to mailing list
  help    Print this message or the help of the given subcommand(s)

spectral kernel quest · kernel test

spectral patch check · format · commit · create · submit · update

Every one of them has --help that says more than this README does — and, for now, a body that panics with a description of what it is supposed to do.

Where to pitch in

Every stub is a small, self-contained function with its signature and doc comment already written, its caller already wired, and a todo!() naming the command it should run. Pick one and the blast radius is that file. No stub needs you to have read the rest of the crate.

Roughly in order of how much they unblock:

patch submit — the most self-contained win. Needs a kernel tree but no network and no scraper.

• patch/maintainers.rs · lookup — run get_maintainer.pl --git over the patch, split the output into To: and Cc:, and collect the files the patch touches
• patch/maintainers.rs · add_cc — fold --cc flags in without duplicates
• patch/mod.rs · submit — the above plus git send-email, with --dry-run stopping one step short

patch check / format / commit / create — the everyday verbs. patch/checkpatch.rs · run already defines the Target enum (working tree, a revision, or a patch file) and Report with an is_clean, so what is missing is the process call and parsing the error/warning counts out of its output.

patch update — small, and worth doing with a test. patch/mod.rs · reroll_path is the naming rule in one pure function: strip one leading vN-, prepend v<revision>-. Re-running it at the same revision should be a no-op, which is easier to assert than to describe.

kernel quest — the fun one, if you like HTML. kernel/quest.rs · Bugzilla::fetch_open is the only place reqwest and scraper earn their place in Cargo.toml; run then applies --filter and picks one. The QuestSource trait is the seam for swapping bugzilla for syzbot or a lore thread later.

kernel test — needs a machine you are willing to boot kernels on. kernel/qemu.rs · build then boot. Streaming serial output as it arrives beats buffering it until qemu exits, which is what makes a boot hang diagnosable.

git.rs — the four plumbing calls. current_branch, diff_against, commit, rev_parse, each a few lines over the run that is already written. Take these if you want to warm up on something tiny.

There are no tests yet. The naming rule in reroll_path and the recipient split in lookup are the two that most want one.

Development

$ cargo fmt --all
$ cargo clippy --all-targets -- -D warnings
$ cargo test

All three are clean on main and are the bar for a change.

A few conventions, in the spirit of keeping the crate reviewable:

• src/cli.rs holds the whole command surface. It is one file on purpose — the CLI is the specification, and reading it top to bottom should tell you what the tool does.
• Command modules return what they produced; main prints it. Output policy, formatting and all, lives in one place.
• Errors go through the one Error enum and ?. The command paths have no unwrap.
• A new stub gets a todo!() that names the command it will end up running. If a whole module is unreachable until its caller exists, it carries a single #[allow(dead_code)] with the reason attached — there are no crate-wide allows, so the warnings come back as the stubs get filled in.
• No unsafe, no FFI.

License

MIT — see LICENSE, © 2026 huntedbytheirs.