From 4ca5c07a1b117fbd183b439a658f26b00bec760b Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 30 Mar 2026 18:14:29 -0700
Subject: [PATCH 1/5] build-manifest: Use zlib-rs

---
 src/tools/build-manifest/Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tools/build-manifest/Cargo.toml b/src/tools/build-manifest/Cargo.toml
index 2b0afae76da4..0b766a3e557c 100644
--- a/src/tools/build-manifest/Cargo.toml
+++ b/src/tools/build-manifest/Cargo.toml
@@ -8,7 +8,7 @@ toml = "0.7"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 anyhow = "1.0.32"
-flate2 = "1.0.26"
+flate2 = { version = "1.1.9", default-features = false, features = ["zlib-rs"] }
 xz2 = "0.1.7"
 tar = "0.4.45"
 sha2 = "0.10.1"

From 3d1fb4c1b337f0edf7199974a0f91182c422d19d Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 30 Mar 2026 18:14:57 -0700
Subject: [PATCH 2/5] rust-installer: Use zlib-rs

---
 src/tools/rust-installer/Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tools/rust-installer/Cargo.toml b/src/tools/rust-installer/Cargo.toml
index e0c93e3c4477..0cb9fa76b2f9 100644
--- a/src/tools/rust-installer/Cargo.toml
+++ b/src/tools/rust-installer/Cargo.toml
@@ -11,7 +11,7 @@ path = "src/main.rs"
 
 [dependencies]
 anyhow = "1.0.19"
-flate2 = "1.0.1"
+flate2 = { version = "1.1.9", default-features = false, features = ["zlib-rs"] }
 rayon = "1.0"
 tar = "0.4.45"
 walkdir = "2"

From 722b2d36269b9dea4893a6ecd55cde31b2df9991 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 30 Mar 2026 18:43:16 -0700
Subject: [PATCH 3/5] Cargo.lock: Update for zlib-rs

---
 Cargo.lock | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index d4c1a02c018a..c1c592da7767 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1422,12 +1422,13 @@ checksum = "3a3076410a55c90011c298b04d0cfa770b00fa04e1e3c97d3f6c9de105a03844"
 
 [[package]]
 name = "flate2"
-version = "1.1.5"
+version = "1.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
 dependencies = [
  "crc32fast",
  "miniz_oxide",
+ "zlib-rs",
 ]
 
 [[package]]
@@ -6944,3 +6945,9 @@ dependencies = [
  "quote",
  "syn 2.0.110",
 ]
+
+[[package]]
+name = "zlib-rs"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3be3d40e40a133f9c916ee3f9f4fa2d9d63435b5fbe1bfc6d9dae0aa0ada1513"

From 3fd1107165b62823e210ec6f1060d9e463b28c22 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 30 Mar 2026 18:57:49 -0700
Subject: [PATCH 4/5] tidy: Allow zlib-rs as a Rust dependency

---
 src/tools/tidy/src/deps.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index c6624b1b3697..b0730de77139 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -504,6 +504,7 @@ pub(crate) struct WorkspaceInfo<'a> {
     "zerotrie",
     "zerovec",
     "zerovec-derive",
+    "zlib-rs",
     // tidy-alphabetical-end
 ];
 

From dd1d5b7f505f0de3585b8d8cab5959fadaa1fcb1 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 30 Mar 2026 19:44:35 -0700
Subject: [PATCH 5/5] citool: use zlib-rs

---
 src/ci/citool/Cargo.lock | 19 +++++++++++++++++--
 src/ci/citool/Cargo.toml |  1 +
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/ci/citool/Cargo.lock b/src/ci/citool/Cargo.lock
index fe1c92f049e0..a208de47256c 100644
--- a/src/ci/citool/Cargo.lock
+++ b/src/ci/citool/Cargo.lock
@@ -170,6 +170,7 @@ dependencies = [
  "clap",
  "csv",
  "diff",
+ "flate2",
  "glob-match",
  "insta",
  "serde",
@@ -344,12 +345,13 @@ checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
 
 [[package]]
 name = "flate2"
-version = "1.1.0"
+version = "1.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11faaf5a5236997af9848be0bef4db95824b1d534ebc64d0f0c6cf3e67bd38dc"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
 dependencies = [
  "crc32fast",
  "miniz_oxide",
+ "zlib-rs",
 ]
 
 [[package]]
@@ -630,6 +632,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3be647b768db090acb35d5ec5db2b0e1f1de11133ca123b9eacf5137868f892a"
 dependencies = [
  "adler2",
+ "simd-adler32",
 ]
 
 [[package]]
@@ -812,6 +815,12 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
+
 [[package]]
 name = "similar"
 version = "2.7.0"
@@ -1187,3 +1196,9 @@ dependencies = [
  "quote",
  "syn",
 ]
+
+[[package]]
+name = "zlib-rs"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3be3d40e40a133f9c916ee3f9f4fa2d9d63435b5fbe1bfc6d9dae0aa0ada1513"
diff --git a/src/ci/citool/Cargo.toml b/src/ci/citool/Cargo.toml
index 0b1f2fe79bf7..f97d5e807fcc 100644
--- a/src/ci/citool/Cargo.toml
+++ b/src/ci/citool/Cargo.toml
@@ -9,6 +9,7 @@ askama = "0.15.4"
 clap = { version = "4.5", features = ["derive"] }
 csv = "1"
 diff = "0.1"
+flate2 = { version = "1.1.9", default-features = false, features = ["zlib-rs"] } # For feature flag only
 glob-match = "0.2"
 serde = { version = "1", features = ["derive"] }
 serde_yaml = "0.9"