diff --git a/docs/cargo.md b/docs/cargo.md
index 7b5669d63e..a80c2a69b5 100644
--- a/docs/cargo.md
+++ b/docs/cargo.md
@@ -32,7 +32,7 @@ A rule for bootstrapping a Rust binary using [Cargo](https://doc.rust-lang.org/c
 | <a id="cargo_bootstrap_repository-repo_mapping"></a>repo_mapping |  A dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.&lt;p&gt;For example, an entry <code>"@foo": "@bar"</code> declares that, for any time this repository depends on <code>@foo</code> (such as a dependency on <code>@foo//some:target</code>, it should actually resolve that dependency within globally-declared <code>@bar</code> (<code>@bar//some:target</code>).   | <a href="https://bazel.build/docs/skylark/lib/dict.html">Dictionary: String -> String</a> | required |  |
 | <a id="cargo_bootstrap_repository-rust_toolchain_repository_template"></a>rust_toolchain_repository_template |  The template to use for finding the host <code>rust_toolchain</code> repository. <code>{version}</code> (eg. '1.53.0'), <code>{triple}</code> (eg. 'x86_64-unknown-linux-gnu'), <code>{system}</code> (eg. 'darwin'), and <code>{arch}</code> (eg. 'aarch64') will be replaced in the string if present.   | String | optional | "rust_{system}_{arch}" |
 | <a id="cargo_bootstrap_repository-srcs"></a>srcs |  Souce files of the crate to build. Passing source files here can be used to trigger rebuilds when changes are made   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
-| <a id="cargo_bootstrap_repository-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.55.0" |
+| <a id="cargo_bootstrap_repository-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.56.0" |
 
 
 <a id="#cargo_build_script"></a>
diff --git a/docs/crate_universe.md b/docs/crate_universe.md
index ead3945b35..012450fa0a 100644
--- a/docs/crate_universe.md
+++ b/docs/crate_universe.md
@@ -162,7 +162,7 @@ Environment Variables:
 | <a id="crate_universe-rust_toolchain_repository_template"></a>rust_toolchain_repository_template |  The template to use for finding the host <code>rust_toolchain</code> repository. <code>{version}</code> (eg. '1.53.0'), <code>{triple}</code> (eg. 'x86_64-unknown-linux-gnu'), <code>{system}</code> (eg. 'darwin'), and <code>{arch}</code> (eg. 'aarch64') will be replaced in the string if present.   | String | optional | "rust_{system}_{arch}" |
 | <a id="crate_universe-sha256s"></a>sha256s |  The sha256 checksum of the desired rust artifacts   | <a href="https://bazel.build/docs/skylark/lib/dict.html">Dictionary: String -> String</a> | optional | {} |
 | <a id="crate_universe-supported_targets"></a>supported_targets |  A list of supported [platform triples](https://doc.rust-lang.org/nightly/rustc/platform-support.html) to consider when resoliving dependencies.   | List of strings | optional | ["aarch64-apple-darwin", "aarch64-unknown-linux-gnu", "x86_64-apple-darwin", "x86_64-pc-windows-msvc", "x86_64-unknown-freebsd", "x86_64-unknown-linux-gnu"] |
-| <a id="crate_universe-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.55.0" |
+| <a id="crate_universe-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.56.0" |
 
 
 <a id="#crate.spec"></a>
diff --git a/docs/flatten.md b/docs/flatten.md
index 1f32578ed4..5e618c789d 100644
--- a/docs/flatten.md
+++ b/docs/flatten.md
@@ -93,7 +93,7 @@ A rule for bootstrapping a Rust binary using [Cargo](https://doc.rust-lang.org/c
 | <a id="cargo_bootstrap_repository-repo_mapping"></a>repo_mapping |  A dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.&lt;p&gt;For example, an entry <code>"@foo": "@bar"</code> declares that, for any time this repository depends on <code>@foo</code> (such as a dependency on <code>@foo//some:target</code>, it should actually resolve that dependency within globally-declared <code>@bar</code> (<code>@bar//some:target</code>).   | <a href="https://bazel.build/docs/skylark/lib/dict.html">Dictionary: String -> String</a> | required |  |
 | <a id="cargo_bootstrap_repository-rust_toolchain_repository_template"></a>rust_toolchain_repository_template |  The template to use for finding the host <code>rust_toolchain</code> repository. <code>{version}</code> (eg. '1.53.0'), <code>{triple}</code> (eg. 'x86_64-unknown-linux-gnu'), <code>{system}</code> (eg. 'darwin'), and <code>{arch}</code> (eg. 'aarch64') will be replaced in the string if present.   | String | optional | "rust_{system}_{arch}" |
 | <a id="cargo_bootstrap_repository-srcs"></a>srcs |  Souce files of the crate to build. Passing source files here can be used to trigger rebuilds when changes are made   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
-| <a id="cargo_bootstrap_repository-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.55.0" |
+| <a id="cargo_bootstrap_repository-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.56.0" |
 
 
 <a id="#crate_universe"></a>
@@ -139,7 +139,7 @@ Environment Variables:
 | <a id="crate_universe-rust_toolchain_repository_template"></a>rust_toolchain_repository_template |  The template to use for finding the host <code>rust_toolchain</code> repository. <code>{version}</code> (eg. '1.53.0'), <code>{triple}</code> (eg. 'x86_64-unknown-linux-gnu'), <code>{system}</code> (eg. 'darwin'), and <code>{arch}</code> (eg. 'aarch64') will be replaced in the string if present.   | String | optional | "rust_{system}_{arch}" |
 | <a id="crate_universe-sha256s"></a>sha256s |  The sha256 checksum of the desired rust artifacts   | <a href="https://bazel.build/docs/skylark/lib/dict.html">Dictionary: String -> String</a> | optional | {} |
 | <a id="crate_universe-supported_targets"></a>supported_targets |  A list of supported [platform triples](https://doc.rust-lang.org/nightly/rustc/platform-support.html) to consider when resoliving dependencies.   | List of strings | optional | ["aarch64-apple-darwin", "aarch64-unknown-linux-gnu", "x86_64-apple-darwin", "x86_64-pc-windows-msvc", "x86_64-unknown-freebsd", "x86_64-unknown-linux-gnu"] |
-| <a id="crate_universe-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.55.0" |
+| <a id="crate_universe-version"></a>version |  The version of cargo the resolver should use   | String | optional | "1.56.0" |
 
 
 <a id="#error_format"></a>
@@ -1782,7 +1782,7 @@ See `load_arbitrary_tool` in `@rules_rust//rust:repositories.bzl` for more detai
 
 | Name  | Description | Default Value |
 | :------------- | :------------- | :------------- |
-| <a id="rust_repositories-version"></a>version |  The version of Rust. Either "nightly", "beta", or an exact version. Defaults to a modern version.   |  <code>"1.55.0"</code> |
+| <a id="rust_repositories-version"></a>version |  The version of Rust. Either "nightly", "beta", or an exact version. Defaults to a modern version.   |  <code>"1.56.0"</code> |
 | <a id="rust_repositories-iso_date"></a>iso_date |  The date of the nightly or beta release (ignored if the version is a specific version).   |  <code>None</code> |
 | <a id="rust_repositories-rustfmt_version"></a>rustfmt_version |  The version of rustfmt. Either "nightly", "beta", or an exact version. Defaults to <code>version</code> if not specified.   |  <code>None</code> |
 | <a id="rust_repositories-edition"></a>edition |  The rust edition to be used by default (2015, 2018 (default), or 2021)   |  <code>None</code> |
diff --git a/docs/rust_repositories.md b/docs/rust_repositories.md
index a0dc3b1a1b..e73bfd95a4 100644
--- a/docs/rust_repositories.md
+++ b/docs/rust_repositories.md
@@ -197,7 +197,7 @@ See `load_arbitrary_tool` in `@rules_rust//rust:repositories.bzl` for more detai
 
 | Name  | Description | Default Value |
 | :------------- | :------------- | :------------- |
-| <a id="rust_repositories-version"></a>version |  The version of Rust. Either "nightly", "beta", or an exact version. Defaults to a modern version.   |  <code>"1.55.0"</code> |
+| <a id="rust_repositories-version"></a>version |  The version of Rust. Either "nightly", "beta", or an exact version. Defaults to a modern version.   |  <code>"1.56.0"</code> |
 | <a id="rust_repositories-iso_date"></a>iso_date |  The date of the nightly or beta release (ignored if the version is a specific version).   |  <code>None</code> |
 | <a id="rust_repositories-rustfmt_version"></a>rustfmt_version |  The version of rustfmt. Either "nightly", "beta", or an exact version. Defaults to <code>version</code> if not specified.   |  <code>None</code> |
 | <a id="rust_repositories-edition"></a>edition |  The rust edition to be used by default (2015, 2018 (default), or 2021)   |  <code>None</code> |
diff --git a/rust/known_shas.bzl b/rust/known_shas.bzl
index e9a2ab31c2..c9d6b57b74 100644
--- a/rust/known_shas.bzl
+++ b/rust/known_shas.bzl
@@ -561,6 +561,64 @@ FILE_KEY_TO_SHA = {
     "2021-09-08/rustfmt-nightly-x86_64-unknown-freebsd": "e1c28472a81312560ca36719f0b61b7212a07d63e85d745f97cd8e3b9ea8f191",
     "2021-09-08/rustfmt-nightly-x86_64-unknown-linux-gnu": "a7d579672b94978e8427584f7e9d2b6534f320719252db46fc6ee85082d646ff",
     "2021-09-08/rustfmt-nightly-x86_64-unknown-linux-musl": "fba0e7bc1401b830223b5207b63808e28403f48d1591c7d47c1681519c1883f7",
+    "2021-10-21/cargo-nightly-aarch64-apple-darwin": "6eba28dffca35b3b8809c0f56e93931ecf75b539d3ca0f048607047b2f3a9588",
+    "2021-10-21/cargo-nightly-aarch64-unknown-linux-gnu": "c91ab0b98bdb80b9136a06e8d6fff33641fad1c9a005559c976db57a5939bb90",
+    "2021-10-21/cargo-nightly-aarch64-unknown-linux-musl": "f0705d665f0721e64673ea8f282980e968fa1186793b7d6530415e0bd05e1711",
+    "2021-10-21/cargo-nightly-x86_64-apple-darwin": "84d04dd97de2e288d7f449006fd81a930ab1d9fddc20299c9aa8f9bcf1b5cbcd",
+    "2021-10-21/cargo-nightly-x86_64-pc-windows-msvc": "2bdd1823caaf95e2bbf8942c35daeb9aed2bf69534bfdb18f2aa8d1e32a0741e",
+    "2021-10-21/cargo-nightly-x86_64-unknown-freebsd": "e578efd5bb719ef96435e2e24969f968ddc00ec1515c86a7fbd01a650976e028",
+    "2021-10-21/cargo-nightly-x86_64-unknown-linux-gnu": "7fc7f3649de6d8aea2304f286d2d1e5ef279b38d88d8fcbb8b81b1a355201273",
+    "2021-10-21/cargo-nightly-x86_64-unknown-linux-musl": "b022b8341aae8c7d698d44a9f69439569385fb6a3c6e5783cf68853513023c10",
+    "2021-10-21/clippy-nightly-aarch64-apple-darwin": "ee11bef6780c3c326ba39c4fb2de53c7b82f3461ad50131811919067bdbc6d21",
+    "2021-10-21/clippy-nightly-aarch64-unknown-linux-gnu": "3e5b3866242c1c3405ab102c205d07bb633fe1884a0b1ef72e1deada91143fa4",
+    "2021-10-21/clippy-nightly-aarch64-unknown-linux-musl": "8666c8dfd127d69531f723210e23675fd372bf72c2c4ea3f853f00e6784c17bc",
+    "2021-10-21/clippy-nightly-x86_64-apple-darwin": "0bfd130526f021f8ee9c003895af276c9978f9da7a03e50d0efe59a73bcda1e2",
+    "2021-10-21/clippy-nightly-x86_64-pc-windows-msvc": "713491e5f7d1a6bb8bfe5433706515fd639b359d5a589ff3ed98a23c187a875f",
+    "2021-10-21/clippy-nightly-x86_64-unknown-freebsd": "6db6b98be1093fdf97a11cec2a87f30c27a10c6e7e96652f7b758f2d7428832b",
+    "2021-10-21/clippy-nightly-x86_64-unknown-linux-gnu": "8deb9bc3831bb90cd49b9ec8763c5a98349b5b47b6622634e64d8d58a2bb33c0",
+    "2021-10-21/clippy-nightly-x86_64-unknown-linux-musl": "effdaf877422d4700dc2ebba543c4186a5e281336c8f415c20482e75abc7f602",
+    "2021-10-21/llvm-tools-nightly-aarch64-apple-darwin": "d6a2bb9d9c097fd3ff15477a95edb77aa6efdae12c5964398e232339b15a955e",
+    "2021-10-21/llvm-tools-nightly-aarch64-unknown-linux-gnu": "8c9d5b9fe646fb39448addf7ee370cbba2c2a229189d38443b17f369dac2f405",
+    "2021-10-21/llvm-tools-nightly-aarch64-unknown-linux-musl": "1dfa08db634e1276d48aa26e5dbc50bf2fde3f2f8ae52dbe5f8ec8fc80bacb76",
+    "2021-10-21/llvm-tools-nightly-x86_64-apple-darwin": "b2331bc949012a35da7c3caccf87dc41f176ffec3c2101f5f2dcc9f83d733483",
+    "2021-10-21/llvm-tools-nightly-x86_64-pc-windows-msvc": "d6aa710e9cb1a8c5913acf2addd40a261f68063e9983441d4396f4443657e467",
+    "2021-10-21/llvm-tools-nightly-x86_64-unknown-freebsd": "85a642dbccf6f8637a5a1ec63e92d61040a9c59319ac1f9e713f5b891b26793b",
+    "2021-10-21/llvm-tools-nightly-x86_64-unknown-linux-gnu": "fa9532d8bd4cfd19626c700601cb73011b00cdd4325c5f5417004a3124d277e1",
+    "2021-10-21/llvm-tools-nightly-x86_64-unknown-linux-musl": "ae10630bd5117da9f5fa5eea27b5624ad864d4d47a291a1f77ca5508c9691762",
+    "2021-10-21/rust-nightly-aarch64-apple-darwin": "5716c620dc210d2575b95f43e7dfe5100f2a8c21651fde66217a506bab96d640",
+    "2021-10-21/rust-nightly-aarch64-unknown-linux-gnu": "b375f0cc8e83dea3c8a32c843492930460736c8bdb6ca3db93e7fa563f312b20",
+    "2021-10-21/rust-nightly-aarch64-unknown-linux-musl": "ddc46ab912d69fe56cd68a74123a08404ce5f0f74551d4433e8632b45114b0dd",
+    "2021-10-21/rust-nightly-x86_64-apple-darwin": "75b66db55f4b0df4592651fc573e4251fa45b3b48b2fdff5a86186f138ff081b",
+    "2021-10-21/rust-nightly-x86_64-pc-windows-msvc": "b15a584bfb4a55719a91b33239664a8eeb55e7f7580e53d947c78bf95b8a034e",
+    "2021-10-21/rust-nightly-x86_64-unknown-freebsd": "74676a2604ca5032307b0dc7865d1833ffde41440d649fd8e083b39e291dbb24",
+    "2021-10-21/rust-nightly-x86_64-unknown-linux-gnu": "778d604ebb1407b59f3d331d986b2d5ead609b2cfe5db6f0ba098375eaee021f",
+    "2021-10-21/rust-nightly-x86_64-unknown-linux-musl": "e7b285da594860356b12d61a5cd6da54e3bffef52b1b5a4f8ffeb1fa86736343",
+    "2021-10-21/rust-std-nightly-aarch64-apple-darwin": "28e2aac0c80e4e62874fe4a97fbeea9dc4482e74964eb1f4e8a83d7531be1a58",
+    "2021-10-21/rust-std-nightly-aarch64-unknown-linux-gnu": "c810f89068c71626ba3326b26cc24d017a76f060eadcd84ad0152b66031bd9f6",
+    "2021-10-21/rust-std-nightly-aarch64-unknown-linux-musl": "212d4f2928e14280bd2ed7a5f35e1a731521da58823f186a685db53711d5db8b",
+    "2021-10-21/rust-std-nightly-wasm32-unknown-unknown": "3db3ab740447206c71e303a9098a0eac2fa14117e4d6e437308239e0d469cb3b",
+    "2021-10-21/rust-std-nightly-wasm32-wasi": "be3ccf5a00e7698b152df33d31406a533ef3fae545d4912e6c3c85b40afd4e25",
+    "2021-10-21/rust-std-nightly-x86_64-apple-darwin": "73a686b2577994bf641a6422338a0cddf4250058df74ccc7540bc6026c53bb3b",
+    "2021-10-21/rust-std-nightly-x86_64-pc-windows-msvc": "1d7f65a9b63a1756d5915c8305930eac747dce5da8583af00f9cff8b803a33ad",
+    "2021-10-21/rust-std-nightly-x86_64-unknown-freebsd": "2903783f094fb121a9171d999aa0d73a255fb5617e4cdad5d8470183758bbb23",
+    "2021-10-21/rust-std-nightly-x86_64-unknown-linux-gnu": "ea390777b60ccd6861e7d163cdf0c19be0b19944039f1b52283120b598f56258",
+    "2021-10-21/rust-std-nightly-x86_64-unknown-linux-musl": "182d763bc6e727f98673ab6ed9d707841e2ea8dd4571bab4f289afb5006b396a",
+    "2021-10-21/rustc-nightly-aarch64-apple-darwin": "1b6a6bf8652751f5123cb7741466cec2164302f3306da92241b2b64103398236",
+    "2021-10-21/rustc-nightly-aarch64-unknown-linux-gnu": "60510d5d77b2d55e3b676bc0e478455452133f3f5dc3c173ba3d251c6b780ec3",
+    "2021-10-21/rustc-nightly-aarch64-unknown-linux-musl": "eef17c07cd783c2a3556785245280b3e0a56290ae4620ce324dffd88caff9785",
+    "2021-10-21/rustc-nightly-x86_64-apple-darwin": "9218bbf8d37c9c6a015abade1129a3b5d37453f144b2999b2f6b569044982ac7",
+    "2021-10-21/rustc-nightly-x86_64-pc-windows-msvc": "62e82a4283298165a0a7d656494d9f6da83cf44e098c337cfd7032acf96d0ebb",
+    "2021-10-21/rustc-nightly-x86_64-unknown-freebsd": "af6c9b69129a4a81fd79481f16f9feb1d4f726859b8d888cffc6fa8231a67c10",
+    "2021-10-21/rustc-nightly-x86_64-unknown-linux-gnu": "0bf65939240f9acbdb08cc4d22b9fb14357d29ee36f4bfc11d4ecc87f07b01db",
+    "2021-10-21/rustc-nightly-x86_64-unknown-linux-musl": "1a9bb9f7cbb5465de5976e75a730dc88a4081ded1f9fb54af1fa514a15b88732",
+    "2021-10-21/rustfmt-nightly-aarch64-apple-darwin": "51d764ca7e1c60fed329b1cbbd2a6a56e5b41f7b728a170745f8a4b4bad10b52",
+    "2021-10-21/rustfmt-nightly-aarch64-unknown-linux-gnu": "2ff4e25789d019047ff451faaf44a67cd155b4c0ec6834487da6cea950bdc2db",
+    "2021-10-21/rustfmt-nightly-aarch64-unknown-linux-musl": "ad433ebb84627c18d4c8b13623f52c46b23f628ef9a3b12e712381c504324960",
+    "2021-10-21/rustfmt-nightly-x86_64-apple-darwin": "589c1412db27f90407147ce3acad3afdb1769d77c1f31156ad6101c317f28490",
+    "2021-10-21/rustfmt-nightly-x86_64-pc-windows-msvc": "49b0163001fd7dd7395f89b408c9909c5b33c4f3147902ec2f77e567bb9d6b9a",
+    "2021-10-21/rustfmt-nightly-x86_64-unknown-freebsd": "d76aca59bb56c6f2e01ab5da9461e058814ba2fed6ebc3abb6bf55ee44a241cf",
+    "2021-10-21/rustfmt-nightly-x86_64-unknown-linux-gnu": "d53c942dc0628ec0214f0eff51ebdd8c70f2bff1293909c908e063c9153144eb",
+    "2021-10-21/rustfmt-nightly-x86_64-unknown-linux-musl": "21b3db961750e8a6ff83d2773e0feb86292fd92fbcda9f3362976b04b9069254",
     "cargo-1.48.0-aarch64-unknown-linux-gnu": "71347016f0da96d4250225f7b52701274df958870b1a65482badb87d661035f9",
     "cargo-1.48.0-aarch64-unknown-linux-musl": "873883a9f6eb2e0cae7dafdc6c4262157298b7bc6ac5c3ed899ed1f55cad7e82",
     "cargo-1.48.0-x86_64-apple-darwin": "ce00d796cf5a9ac8d88d9df94c408e5d7ccd3541932a829eae833cc8e57efb15",
@@ -632,6 +690,14 @@ FILE_KEY_TO_SHA = {
     "cargo-1.55.0-x86_64-unknown-freebsd": "f574b15dee6c52f25076bb657f3e3129b5828a2617c82f2e1c4101e0bd21a880",
     "cargo-1.55.0-x86_64-unknown-linux-gnu": "bb18c74aea07fa29c7169ce78756dfd08c07da08c584874e09fa6929c8267ec1",
     "cargo-1.55.0-x86_64-unknown-linux-musl": "d91efc8e7a71845dcec9ec7db1edb6765cba5ded69d3ab734f549d6875b52e97",
+    "cargo-1.56.0-aarch64-apple-darwin": "ced26df8edddcb7ebdedd2997b9005fc9a849e57b1b82f3aeba9241039f7b958",
+    "cargo-1.56.0-aarch64-unknown-linux-gnu": "3a3b0b74a18247db46badc1e94285fe5e60ad0e9c18fd2dbf15878aa56a5994a",
+    "cargo-1.56.0-aarch64-unknown-linux-musl": "bf24b7df97d93d61f6c1ed8382d99400c4197939502b14904c40ef96bb2abab5",
+    "cargo-1.56.0-x86_64-apple-darwin": "63b6558712050e7f8c57cac0b5b7cb2cafc125d157d9f4bd82f6f47b4648ed0d",
+    "cargo-1.56.0-x86_64-pc-windows-msvc": "319ae8cde721f611ddf673a4aad21b145aec6577ccb75d40ad0856cbab9a2cfe",
+    "cargo-1.56.0-x86_64-unknown-freebsd": "e1e7400a16c7cb1d2ac83e567c8c23f04fb6ccfcb7b6d1978d327da6edc879f6",
+    "cargo-1.56.0-x86_64-unknown-linux-gnu": "e74bd0038893e76393f67a58786ec33ef9251cdb65550b3a2a8117c7355ead71",
+    "cargo-1.56.0-x86_64-unknown-linux-musl": "efadb9f545b6ce49d4a861ae7e75f0ce02a6fedb9e5b30e7810dcb4854ca6799",
     "clippy-1.48.0-aarch64-unknown-linux-gnu": "2cc894bf75d938c0f7b96c7711d93b6d5a0befed5c09232cdd8413a57942ed88",
     "clippy-1.48.0-aarch64-unknown-linux-musl": "b3d740358470df6f4c1881a40db16c6fce4082bd251b012963147fdadab96879",
     "clippy-1.48.0-x86_64-apple-darwin": "d70a5d224a90df3fc77d7bd38df931023a3966be755b888bf0888d6bfcbdc424",
@@ -703,6 +769,14 @@ FILE_KEY_TO_SHA = {
     "clippy-1.55.0-x86_64-unknown-freebsd": "ba035cd7f62468fc75a56f604ac3579adce4f90ba2e6df219299f21668def51f",
     "clippy-1.55.0-x86_64-unknown-linux-gnu": "108ebbc6b311fc0cafc125f1fd7f35a82935000c60cad49a565958e47f63193f",
     "clippy-1.55.0-x86_64-unknown-linux-musl": "e248a8b3987c2750439966ed5df385a089147079105d85041a8147b1044b4f3c",
+    "clippy-1.56.0-aarch64-apple-darwin": "70eb9ec3d9ab79c20030bd0df903ff972dea451dd2a4b55c7eaa8837c1782071",
+    "clippy-1.56.0-aarch64-unknown-linux-gnu": "fb62502c82cf35fecc55761fb3f7a816d2d355cb31ad89fa844be4a1368853de",
+    "clippy-1.56.0-aarch64-unknown-linux-musl": "fb1852dbeff93f1518ae3d0f7adfeb95596aa55069ad24dbcda14e59bd9ec9a2",
+    "clippy-1.56.0-x86_64-apple-darwin": "9410b2f7096ecc3f495fc8a36e14bd566fdd3e6fda2923b4732c3055da81fcf7",
+    "clippy-1.56.0-x86_64-pc-windows-msvc": "cdca7f40793889dca4eb19b846c7ca7bc60ffd8f5cc2fa20c6c71b66c26e9449",
+    "clippy-1.56.0-x86_64-unknown-freebsd": "c5751a4a7043c7a29755459193cde2a1468b4a0726fb3b188853afc6d6870510",
+    "clippy-1.56.0-x86_64-unknown-linux-gnu": "52b49ecc5d44d7f83983ad1aaa37ed9d0ac86a72395cef9e31d06f4ba2343c03",
+    "clippy-1.56.0-x86_64-unknown-linux-musl": "32b7b596225dedf38f9228edd1fde9211f6bd1969f924c3de7cc0d5150577487",
     "llvm-tools-1.36.0-aarch64-unknown-linux-gnu": "942856e49837a1c3b9c7d48b52cf0ac0fcb2bb31bb691fe53bfb934afb561c7f",
     "llvm-tools-1.36.0-x86_64-apple-darwin": "ed702a4174a27fcf118f301e79835c3da205d3d98adb4acc294b72293a2ec790",
     "llvm-tools-1.36.0-x86_64-pc-windows-msvc": "cf72242bcf873227c026505f56f3ffdaa2febde828d67ad7fc04c4a2e72d7587",
@@ -846,6 +920,14 @@ FILE_KEY_TO_SHA = {
     "llvm-tools-1.55.0-x86_64-unknown-freebsd": "f186caf30fadf738275f4daf077815445b4c3496cc7d3e85fbf53b5f8f57eb21",
     "llvm-tools-1.55.0-x86_64-unknown-linux-gnu": "ebad576075c4dd039444ca7335ff244d6c0c566a7ee1532ac80d36a2de1217a5",
     "llvm-tools-1.55.0-x86_64-unknown-linux-musl": "28de296a08d173bf5bad236935ccc547c8eb741fb91900cb10499e80e2472ec5",
+    "llvm-tools-1.56.0-aarch64-apple-darwin": "4ad514255a87b0aba52bf995cb999bc7b34d42419b675fd757664d6682a45210",
+    "llvm-tools-1.56.0-aarch64-unknown-linux-gnu": "9518804888281bd1b0c8d8467d7c3e312342649ce3660248728a8d4faa193564",
+    "llvm-tools-1.56.0-aarch64-unknown-linux-musl": "095acf10efb3a4561758da9f9374488ab73c88a2f78b6d1ee97147ac8f039fe9",
+    "llvm-tools-1.56.0-x86_64-apple-darwin": "e40341be6619513f50bf89d445e3b30696853f3553bbe98fa9aa3527cd7c49cd",
+    "llvm-tools-1.56.0-x86_64-pc-windows-msvc": "838bf630fdaa404f9899a92e58c1b5646f4f4b6d54729e4f1c3aade5585a74f7",
+    "llvm-tools-1.56.0-x86_64-unknown-freebsd": "05225a9aeb481757b470ee604a129bfc7707d85dc487fffcc2585f4124e012d9",
+    "llvm-tools-1.56.0-x86_64-unknown-linux-gnu": "ac54b5c1bae0955945cd779291bc443b3e6d52f217ce1078a3505bae1c0e2ff2",
+    "llvm-tools-1.56.0-x86_64-unknown-linux-musl": "9512db06f3090028b0ba26aeea21c3a80e6676177c92cfa1e60d13acd6871f0e",
     "rust-1.26.0-aarch64-unknown-linux-gnu": "e12dc84bdb569cdb382268a5fe6ae6a8e2e53810cb890ec3a7133c20ba8451ac",
     "rust-1.26.0-x86_64-apple-darwin": "38708803c3096b8f101d1919ee2d7e723b0adf1bc1bb986b060973b57d8c7c28",
     "rust-1.26.0-x86_64-pc-windows-msvc": "20631bf942242d4be82363030839851bf18a2199b74a661bdc334f830e9e1d5a",
@@ -1080,6 +1162,14 @@ FILE_KEY_TO_SHA = {
     "rust-1.55.0-x86_64-unknown-freebsd": "7ddb8ec4d431f64dd6428df93d46f726516970b0ca83c71c3efbfe34a42d3113",
     "rust-1.55.0-x86_64-unknown-linux-gnu": "2080253a2ec36ac8ed6e060d30802d888533124b8d16545cfd4af898b365eaac",
     "rust-1.55.0-x86_64-unknown-linux-musl": "f24f68587253c4bfbe59d3d10fe4897068d9130538de6b2d02097a25718030c2",
+    "rust-1.56.0-aarch64-apple-darwin": "31b7e9c8b4ac3133b1952d1278077fa45250e26758625f972f9b2f4e2426709d",
+    "rust-1.56.0-aarch64-unknown-linux-gnu": "f3e9a9c8af7d17a2fbe0ce561a7dc42f65c5444025783f1f63cd47960a534a9e",
+    "rust-1.56.0-aarch64-unknown-linux-musl": "a97c8f305c0dd07925a00f90e135152769f1c97442874691ffc865602209066d",
+    "rust-1.56.0-x86_64-apple-darwin": "577faef3f118a4a259e5e61a415b06434081baeceeff7bbf2357456cfc5b8735",
+    "rust-1.56.0-x86_64-pc-windows-msvc": "7ebee9ae583d0723d945fe89244fbc6f51f8723d318a2be9bcbe1e4ffc33606f",
+    "rust-1.56.0-x86_64-unknown-freebsd": "e31a47ecdd223ef7c84fc50d2c51343f8a3e54d419b04e17d143bd81ed587a7f",
+    "rust-1.56.0-x86_64-unknown-linux-gnu": "5189cd56447f9d56fcd7a1966efe5a8efd19843fdfd6bf9a23a9acbc57b5e3f9",
+    "rust-1.56.0-x86_64-unknown-linux-musl": "6ad1c6fa11e3bce86368385d0b0512d723a426fa55bcaeafdab08d03f127275d",
     "rust-src-1.26.0": "d02fe6fd5c0f330656e9ff0a290ebf23cab7c909f96ce1838247fadc117eb1dd",
     "rust-src-1.26.1": "19ef8113ae53ec7ea8f6772a5c9ce5a3dfc28b1bddd800841fb5bbec33fa3619",
     "rust-src-1.26.2": "d63cb7ca67f1bb2101898b7ca33105eeb6d9d9cc3e7ff566b90b0321ec448e73",
@@ -1119,6 +1209,7 @@ FILE_KEY_TO_SHA = {
     "rust-src-1.53.0": "26b1464bd313ae99de27a162ca96b4fb321e4414448ea8ce8abd715ef8c7ba2b",
     "rust-src-1.54.0": "56d14ee97c59c543291154ab427cf96a1a82ef5cf32b89f14886dcfc01f5310b",
     "rust-src-1.55.0": "3be79e301246b413e9e1cc4b5b4f53bcbc964482005381a899ab6c597bef7996",
+    "rust-src-1.56.0": "00c2225d0e1d430b1632373c46448b1b69839032b8384684091bb9cce19b2ce6",
     "rust-std-1.26.0-aarch64-unknown-linux-gnu": "a583ddc2d4b5f9516bf136f781268ae0e813295d1d145fab4b46a4220f448923",
     "rust-std-1.26.0-aarch64-unknown-linux-musl": "6a112ecd4cdefee2688bf69fdceb785a4d08cea33ba32296539abe3cb7f5eae1",
     "rust-std-1.26.0-wasm32-unknown-unknown": "0f8bb8bdb523cd05acd11006d47b14d7589e64fe25a43d1aec5df692988b400f",
@@ -1460,6 +1551,16 @@ FILE_KEY_TO_SHA = {
     "rust-std-1.55.0-x86_64-unknown-freebsd": "522f4f75c50a0fde08d6235ed80c7cac30c922943954aad1e7c154cd8762ddd3",
     "rust-std-1.55.0-x86_64-unknown-linux-gnu": "c07c5ce96b86364601c0c471bb85105e80a5e345b3e4b3e2674e541cc2fdefcf",
     "rust-std-1.55.0-x86_64-unknown-linux-musl": "357b8f56ffa3858e2f32be837bd84e3d89403f17c55bf0c105f34a0b796bceed",
+    "rust-std-1.56.0-aarch64-apple-darwin": "88ae1a2da1c7bbabeab3bce392ed9cdf1403c1f6cef5a8bc9a6813e480127fc6",
+    "rust-std-1.56.0-aarch64-unknown-linux-gnu": "061c8a855696b3e23fb48ad69aa90e70ead825825e4cc02374d3cb1df4486258",
+    "rust-std-1.56.0-aarch64-unknown-linux-musl": "2a83ec23e14e0b578b636c3c95283c92fd034e8b56a564c043db3f8b746eeb2e",
+    "rust-std-1.56.0-wasm32-unknown-unknown": "3e0f1282549f09f9f9062f8fa8ca197eba5407c4422378688d78075bdfaf3358",
+    "rust-std-1.56.0-wasm32-wasi": "f819c096dcfc3fd0466eff346ea4291fe0ef86a08529b9be6843017c79256237",
+    "rust-std-1.56.0-x86_64-apple-darwin": "58c6fad6f09706f2940cd501a1d0dbd984ce4926000009aed313dd2cd3c1a7ad",
+    "rust-std-1.56.0-x86_64-pc-windows-msvc": "7d3961a5115f29738061d9c22e2472082a5e2de7bfe550a04a22180c3caa472c",
+    "rust-std-1.56.0-x86_64-unknown-freebsd": "e059d39f15cea58fd89d860a06504f48234ae2aff2c1eb5e4463b50367827ff7",
+    "rust-std-1.56.0-x86_64-unknown-linux-gnu": "3c314efa230f95f5d9e3357e5f915a4f40d2a21b10ba7b92fcc9036cbcd9fbac",
+    "rust-std-1.56.0-x86_64-unknown-linux-musl": "03b7a319a3d3e5f86278753f2780c7b3fa3f1b60bc2b8ddf6fd18a36540b8601",
     "rustc-1.26.0-aarch64-unknown-linux-gnu": "ddddaddb585b95d81854171ac4e02d07790505853cee3034f199c8b7897f32e2",
     "rustc-1.26.0-x86_64-apple-darwin": "5cb67314656d16cf2a1bdc84213aaaf6afdb5811825c7afba916e2d42d3d641f",
     "rustc-1.26.0-x86_64-pc-windows-msvc": "427ae4a43a901be288ff3a4dc85d3a14f7e95108cfdaae63e8dbb4a227e07cdd",
@@ -1694,6 +1795,14 @@ FILE_KEY_TO_SHA = {
     "rustc-1.55.0-x86_64-unknown-freebsd": "ad50ba2c87acb59020959df594aadc207f4fa527b2b2cd8849f3b1d3f666986f",
     "rustc-1.55.0-x86_64-unknown-linux-gnu": "9da098b2df01124f2c4b9789767151521f4bab98f50befdc75a691cece0c0d00",
     "rustc-1.55.0-x86_64-unknown-linux-musl": "f7c1fe2393db842630b23ecf6164fac471b11235fdb62a35a86e7cd3cf8d749c",
+    "rustc-1.56.0-aarch64-apple-darwin": "c588dc2cd352eaf27ae74ee593bd0aaa65ac2742416c714f5827f395bb7c19df",
+    "rustc-1.56.0-aarch64-unknown-linux-gnu": "eb7283729bc4c336aa23b020489e8feb78eed70831213ee2e4121ce7d6ac33f4",
+    "rustc-1.56.0-aarch64-unknown-linux-musl": "e312187386bfb39fde04ca007faf656179e8c2b1bb1a0d59007db7a247b54b4e",
+    "rustc-1.56.0-x86_64-apple-darwin": "a724945de2bb0ba78e56217ba02f67ad0cb07a01c2438b01b91f85fb94d273d2",
+    "rustc-1.56.0-x86_64-pc-windows-msvc": "1034b2f6150d892649c1eb8fb10dbb4228ca2010f88720795e6a12696cab369a",
+    "rustc-1.56.0-x86_64-unknown-freebsd": "4e7a2f62ef2873b3bd45749133c1690c4b0e037af5a586e9ea691e480f8d2d40",
+    "rustc-1.56.0-x86_64-unknown-linux-gnu": "aa66db89c3f89325e40ba0bfe481f4d631559884ae4812c3c3d091d80ba7c245",
+    "rustc-1.56.0-x86_64-unknown-linux-musl": "5f7ed6c289b56c129d6dbb407348f566caf39cfc5db35a4b6253cf514940482e",
     "rustfmt-1.48.0-aarch64-unknown-linux-gnu": "28f7d1ef37c034033eb0e30a13e5f0ad5bbc506adb8a8a9c03adce2b0d4842d5",
     "rustfmt-1.48.0-aarch64-unknown-linux-musl": "e6efa0fae347f97dca3b892565302d35b4cedfee7cb6e2b5fcdb2801074fe018",
     "rustfmt-1.48.0-x86_64-apple-darwin": "cfe593a9446e7dfa52ded8a7cca174ba0c2d1cac6e865d04e0890282f25d22e2",
@@ -1765,4 +1874,12 @@ FILE_KEY_TO_SHA = {
     "rustfmt-1.55.0-x86_64-unknown-freebsd": "5317af05afbcfde0fae7ba4ad5404901b0c611d826c7dd38926a8b08ade53c72",
     "rustfmt-1.55.0-x86_64-unknown-linux-gnu": "ecb58add71d3f3cf8a213fe7b531bc230f8da5cecd835cee6429e76798b548cc",
     "rustfmt-1.55.0-x86_64-unknown-linux-musl": "33bd862bbc9b54745c3e1d400440996fd0e6759c4d482f1a888ba8fafab29c3a",
+    "rustfmt-1.56.0-aarch64-apple-darwin": "0c1dcc80d2028748c38a4c3360048940a887ca899af577e9f3026c3d1a359469",
+    "rustfmt-1.56.0-aarch64-unknown-linux-gnu": "3dabc693866f74a956b99f8cac1f1beca6dbc38de6cc095ccdacbdccc18b4350",
+    "rustfmt-1.56.0-aarch64-unknown-linux-musl": "9d1b9405dc2cbeb7ff7f2ecb468a42d7a36429e642714de1605eb242947afc88",
+    "rustfmt-1.56.0-x86_64-apple-darwin": "f8fc28492af2fece8915db0959bb5af354706d63556854f4c149e6dbc9f3c11b",
+    "rustfmt-1.56.0-x86_64-pc-windows-msvc": "1080a5e5f3957eed2799ce65adf93b8bd8c0a9233c5149d8992c339fe7acab31",
+    "rustfmt-1.56.0-x86_64-unknown-freebsd": "a5e58bbf9407ac7da18df4d385f0988d299b1a71d18ce39fb7d1de15c007f5a6",
+    "rustfmt-1.56.0-x86_64-unknown-linux-gnu": "ce14465427e5919e407af9e58fea0a638aa02515f182a1a1c0b740cbd52a5e5a",
+    "rustfmt-1.56.0-x86_64-unknown-linux-musl": "98dbc11edb80de0c1303823f890434406c36501d89ee45ba2137d4ef4220db8a",
 }
diff --git a/rust/private/common.bzl b/rust/private/common.bzl
index 7baf10ce94..16af470e09 100644
--- a/rust/private/common.bzl
+++ b/rust/private/common.bzl
@@ -31,7 +31,7 @@ load(":providers.bzl", "CrateInfo", "DepInfo", "StdLibInfo")
 #
 # Note: Code in `.github/workflows/crate_universe.yaml` looks for this line, if
 # you remove it or change its format, you will also need to update that code.
-DEFAULT_RUST_VERSION = "1.55.0"
+DEFAULT_RUST_VERSION = "1.56.0"
 DEFAULT_RUST_EDITION = "2018"
 
 def _create_crate_info(**kwargs):
diff --git a/util/fetch_shas_NIGHTLY_ISO_DATES.txt b/util/fetch_shas_NIGHTLY_ISO_DATES.txt
index 9d1b346ea7..bc39789209 100644
--- a/util/fetch_shas_NIGHTLY_ISO_DATES.txt
+++ b/util/fetch_shas_NIGHTLY_ISO_DATES.txt
@@ -6,3 +6,4 @@
 2020-12-30
 2021-06-16
 2021-09-08
+2021-10-21
diff --git a/util/fetch_shas_VERSIONS.txt b/util/fetch_shas_VERSIONS.txt
index bb235fe36e..c0e7c3fcc8 100644
--- a/util/fetch_shas_VERSIONS.txt
+++ b/util/fetch_shas_VERSIONS.txt
@@ -37,3 +37,4 @@
 1.53.0
 1.54.0
 1.55.0
+1.56.0