diff --git a/ci/docker-rust-nightly/Dockerfile b/ci/docker-rust-nightly/Dockerfile
index 9807fd4c93..469ea91b6d 100644
--- a/ci/docker-rust-nightly/Dockerfile
+++ b/ci/docker-rust-nightly/Dockerfile
@@ -1,4 +1,4 @@
-FROM solanalabs/rust:1.54.0
+FROM solanalabs/rust:1.55.0
 ARG date
 
 RUN set -x \
diff --git a/ci/docker-rust/Dockerfile b/ci/docker-rust/Dockerfile
index fd4b3ce241..095616c11a 100644
--- a/ci/docker-rust/Dockerfile
+++ b/ci/docker-rust/Dockerfile
@@ -1,6 +1,6 @@
 # Note: when the rust version is changed also modify
 # ci/rust-version.sh to pick up the new image tag
-FROM rust:1.54.0
+FROM rust:1.55.0
 
 # Add Google Protocol Buffers for Libra's metrics library.
 ENV PROTOC_VERSION 3.8.0
@@ -14,11 +14,10 @@ RUN set -x \
  && apt update \
  && apt install -y \
       buildkite-agent \
-      clang-7 \
+      clang \
       cmake \
       lcov \
       libudev-dev \
-      libclang-common-7-dev \
       mscgen \
       net-tools \
       rsync \
diff --git a/ci/rust-version.sh b/ci/rust-version.sh
index 8a001815a3..a0b22e78a6 100644
--- a/ci/rust-version.sh
+++ b/ci/rust-version.sh
@@ -18,13 +18,13 @@
 if [[ -n $RUST_STABLE_VERSION ]]; then
   stable_version="$RUST_STABLE_VERSION"
 else
-  stable_version=1.54.0
+  stable_version=1.55.0
 fi
 
 if [[ -n $RUST_NIGHTLY_VERSION ]]; then
   nightly_version="$RUST_NIGHTLY_VERSION"
 else
-  nightly_version=2021-08-02
+  nightly_version=2021-10-05
 fi
 
 
diff --git a/programs/bpf/rust/invoke/src/processor.rs b/programs/bpf/rust/invoke/src/processor.rs
index 408da14432..b76762c56a 100644
--- a/programs/bpf/rust/invoke/src/processor.rs
+++ b/programs/bpf/rust/invoke/src/processor.rs
@@ -477,51 +477,27 @@ fn process_instruction(
             let owner = *accounts[FROM_INDEX].owner;
             let ptr = accounts[FROM_INDEX].data.borrow().as_ptr() as u64 as *mut _;
             let len = accounts[FROM_INDEX].data_len();
-            let mut data = unsafe { std::slice::from_raw_parts_mut(ptr, len) };
+            let data = unsafe { std::slice::from_raw_parts_mut(ptr, len) };
             let mut lamports = accounts[FROM_INDEX].lamports();
-            let from_info = AccountInfo::new(
-                &pubkey,
-                false,
-                true,
-                &mut lamports,
-                &mut data,
-                &owner,
-                false,
-                0,
-            );
+            let from_info =
+                AccountInfo::new(&pubkey, false, true, &mut lamports, data, &owner, false, 0);
 
             let pubkey = *accounts[DERIVED_KEY1_INDEX].key;
             let owner = *accounts[DERIVED_KEY1_INDEX].owner;
             // Point to top edge of heap, attempt to allocate into unprivileged memory
-            let mut data = unsafe { std::slice::from_raw_parts_mut(0x300007ff8 as *mut _, 0) };
+            let data = unsafe { std::slice::from_raw_parts_mut(0x300007ff8 as *mut _, 0) };
             let mut lamports = accounts[DERIVED_KEY1_INDEX].lamports();
-            let derived_info = AccountInfo::new(
-                &pubkey,
-                false,
-                true,
-                &mut lamports,
-                &mut data,
-                &owner,
-                false,
-                0,
-            );
+            let derived_info =
+                AccountInfo::new(&pubkey, false, true, &mut lamports, data, &owner, false, 0);
 
             let pubkey = *accounts[SYSTEM_PROGRAM_INDEX].key;
             let owner = *accounts[SYSTEM_PROGRAM_INDEX].owner;
             let ptr = accounts[SYSTEM_PROGRAM_INDEX].data.borrow().as_ptr() as u64 as *mut _;
             let len = accounts[SYSTEM_PROGRAM_INDEX].data_len();
-            let mut data = unsafe { std::slice::from_raw_parts_mut(ptr, len) };
+            let data = unsafe { std::slice::from_raw_parts_mut(ptr, len) };
             let mut lamports = accounts[SYSTEM_PROGRAM_INDEX].lamports();
-            let system_info = AccountInfo::new(
-                &pubkey,
-                false,
-                false,
-                &mut lamports,
-                &mut data,
-                &owner,
-                true,
-                0,
-            );
+            let system_info =
+                AccountInfo::new(&pubkey, false, false, &mut lamports, data, &owner, true, 0);
 
             let instruction = system_instruction::create_account(
                 accounts[FROM_INDEX].key,
diff --git a/runtime/src/append_vec.rs b/runtime/src/append_vec.rs
index 7811e91afe..fc7bbb2bb4 100644
--- a/runtime/src/append_vec.rs
+++ b/runtime/src/append_vec.rs
@@ -895,6 +895,7 @@ pub mod tests {
             // assert_eq! thinks *executable_bool is equal to false but the if condition thinks it's not, contradictorily.
             assert!(!*executable_bool);
             const FALSE: bool = false; // keep clippy happy
+            #[allow(clippy::if_then_panic)]
             if *executable_bool == FALSE {
                 panic!("This didn't occur if this test passed.");
             }