Rust workspace crates

The top-level Cargo.toml defines a Rust workspace whose members are built and tested as first-class targets by mach. Their transitive dependencies are vendored under third_party/rust/.

Members

Crate	Path	Purpose
nmhproxy	browser/app/nmhproxy/	Native messaging proxy
mozjs build crate	js/src/rust	SpiderMonkey Rust crate
idna_glue	netwerk/base/idna_glue	IDNA host name parsing
http3server (test only)	netwerk/test/http3server	HTTP/3 test server
abridged_certs	security/manager/ssl/abridged_certs	Abridged certs format
ipcclientcerts	security/manager/ssl/ipcclientcerts	Client cert IPC
osclientcerts	security/manager/ssl/osclientcerts	OS-keystore-backed client certs
pkcs11testmodule (test)	security/manager/ssl/tests/unit/pkcs11testmodule
test_trust_anchors (test)	security/manager/ssl/tests/unit/test_trust_anchors
trust_anchors	security/manager/ssl/trust_anchors	Built-in CA trust store
mls_gk	security/mls/mls_gk	Messaging Layer Security gatekeeper
geckodriver	testing/geckodriver	W3C WebDriver server
uniffi-bindgen-gecko-js	toolkit/components/uniffi-bindgen-gecko-js	UniFFI JS binding generator
crashreporter app	toolkit/crashreporter/client/app	Crash reporter Rust UI
crash_helper_server	toolkit/crashreporter/crash_helper_server	OOP crash collector
crash_helper_client	toolkit/crashreporter/crash_helper_client	Client lib
minidump-analyzer (Android export)	toolkit/crashreporter/minidump-analyzer/android/export
mozwer-rust	toolkit/crashreporter/mozwer-rust	Windows Error Reporting integration
gtest_rust	toolkit/library/gtest/rust	Test stub crate
xul (rust)	toolkit/library/rust/	The Rust half of libxul

The list of root crates above comes directly from the [workspace] members array in Cargo.toml.

Other Rust in the tree

• Stylo (servo/components/style/) — built as a library and linked into libxul.
• WebRender (gfx/wr/) — likewise.
• Neqo glue — workspace member referenced in the Cargo.toml defaults.
• dav1d / rav1d — AV1 decoding; vendored.
• wgpu — WebGPU; vendored.

Vendoring

./mach vendor rust

regenerates third_party/rust/ and updates Cargo.lock. The supply-chain audit policy lives in supply-chain/ and uses cargo-vet under the hood.

Related

• Build system
• Vendored third-party