RustPython · youknowone · Jun 3, 2026 · May 1, 2026
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -49,7 +49,7 @@
 flamescope = { version = "0.1.2", optional = true }

 rustls = { workspace = true, optional = true }
 rustls-graviola = { workspace = true, optional = true }

 [target.'cfg(windows)'.dependencies]
 libc = { workspace = true }
@@ -236,8 +236,8 @@
 libc = "0.2.186"
 libffi = "5"
 libloading = "0.9"
-liblzma = "0.4"
-liblzma-sys = "0.4"
+xz = "0.4.6-rc.0"
+xz-sys = "0.4.6-rc.0"
 libsqlite3-sys = "0.37"
 libz-rs-sys = "0.6"
 lock_api = "0.4"

diff --git a/crates/stdlib/Cargo.toml b/crates/stdlib/Cargo.toml
@@ -92,7 +92,7 @@

 # tkinter
 tk-sys = { workspace = true, optional = true }
 tcl-sys = { workspace = true, optional = true }
 widestring = { workspace = true, optional = true }
 chrono.workspace = true

@@ -117,8 +117,8 @@
 rustls = { workspace = true, default-features = false, features = ["std", "tls12"], optional = true }
 rustls-native-certs = { workspace = true, optional = true }
 rustls-pemfile = { workspace = true, optional = true }
 rustls-platform-verifier = { workspace = true, optional = true }
 x509-cert = { workspace = true, features = ["pem", "builder"], optional = true }
 x509-parser = { workspace = true, optional = true }
 der = { workspace = true, optional = true }
 pem-rfc7468 = { workspace = true, features = ["alloc"], optional = true }
@@ -128,8 +128,8 @@
 
 [target.'cfg(not(any(target_os = "android", target_arch = "wasm32")))'.dependencies]
 libsqlite3-sys = { workspace = true, features = ["bundled"], optional = true }
-liblzma = { workspace = true }
-liblzma-sys = { workspace = true }
+xz = { workspace = true }
+xz-sys = { workspace = true }
 
 [target.'cfg(windows)'.dependencies]
 paste = { workspace = true }

diff --git a/crates/stdlib/src/lzma.rs b/crates/stdlib/src/lzma.rs
@@ -9,62 +9,60 @@ mod _lzma {
         DecompressError, DecompressState, DecompressStatus, Decompressor,
     };
     use alloc::fmt;
-    use liblzma::stream::{
+    use xz::stream::{
         Action, Check, Error, Filters, LzmaOptions, MatchFinder, Mode, Status, Stream,
         TELL_ANY_CHECK, TELL_NO_CHECK,
     };
     // lzma_check, lzma_mode, lzma_match_finder have platform-dependent signedness
     // (i32 on Windows, u32 elsewhere). Define as fixed-type const to avoid mismatch.
+    use rustpython_common::lock::PyMutex;
+    use rustpython_vm::builtins::{PyBaseExceptionRef, PyBytesRef, PyDict, PyType, PyTypeRef};
+    use rustpython_vm::convert::ToPyException;
+    use rustpython_vm::function::ArgBytesLike;
+    use rustpython_vm::types::Constructor;
+    use rustpython_vm::{Py, PyObjectRef, PyPayload, PyResult, VirtualMachine};
     #[pyattr]
-    use liblzma_sys::{
+    use xz_sys::{
         LZMA_FILTER_ARM as FILTER_ARM, LZMA_FILTER_ARMTHUMB as FILTER_ARMTHUMB,
         LZMA_FILTER_DELTA as FILTER_DELTA, LZMA_FILTER_IA64 as FILTER_IA64,
         LZMA_FILTER_LZMA1 as FILTER_LZMA1, LZMA_FILTER_LZMA2 as FILTER_LZMA2,
         LZMA_FILTER_POWERPC as FILTER_POWERPC, LZMA_FILTER_SPARC as FILTER_SPARC,
         LZMA_FILTER_X86 as FILTER_X86,
     };
     #[pyattr]
-    use liblzma_sys::{
-        LZMA_PRESET_DEFAULT as PRESET_DEFAULT, LZMA_PRESET_EXTREME as PRESET_EXTREME,
-    };
-    use rustpython_common::lock::PyMutex;
-    use rustpython_vm::builtins::{PyBaseExceptionRef, PyBytesRef, PyDict, PyType, PyTypeRef};
-    use rustpython_vm::convert::ToPyException;
-    use rustpython_vm::function::ArgBytesLike;
-    use rustpython_vm::types::Constructor;
-    use rustpython_vm::{Py, PyObjectRef, PyPayload, PyResult, VirtualMachine};
+    use xz_sys::{LZMA_PRESET_DEFAULT as PRESET_DEFAULT, LZMA_PRESET_EXTREME as PRESET_EXTREME};
 
     const BUFSIZ: usize = 8192;
 
-    // liblzma_sys enum types have platform-dependent signedness; `as _` normalizes to i32
+    // xz_sys enum types have platform-dependent signedness; `as _` normalizes to i32
     #[pyattr]
-    const CHECK_NONE: i32 = liblzma_sys::LZMA_CHECK_NONE as _;
+    const CHECK_NONE: i32 = xz_sys::LZMA_CHECK_NONE as _;
     #[pyattr]
-    const CHECK_CRC32: i32 = liblzma_sys::LZMA_CHECK_CRC32 as _;
+    const CHECK_CRC32: i32 = xz_sys::LZMA_CHECK_CRC32 as _;
     #[pyattr]
-    const CHECK_CRC64: i32 = liblzma_sys::LZMA_CHECK_CRC64 as _;
+    const CHECK_CRC64: i32 = xz_sys::LZMA_CHECK_CRC64 as _;
     #[pyattr]
-    const CHECK_SHA256: i32 = liblzma_sys::LZMA_CHECK_SHA256 as _;
+    const CHECK_SHA256: i32 = xz_sys::LZMA_CHECK_SHA256 as _;
     #[pyattr]
     const CHECK_ID_MAX: i32 = 15;
     #[pyattr]
     const CHECK_UNKNOWN: i32 = CHECK_ID_MAX + 1;
 
     #[pyattr]
-    const MF_HC3: i32 = liblzma_sys::LZMA_MF_HC3 as _;
+    const MF_HC3: i32 = xz_sys::LZMA_MF_HC3 as _;
     #[pyattr]
-    const MF_HC4: i32 = liblzma_sys::LZMA_MF_HC4 as _;
+    const MF_HC4: i32 = xz_sys::LZMA_MF_HC4 as _;
     #[pyattr]
-    const MF_BT2: i32 = liblzma_sys::LZMA_MF_BT2 as _;
+    const MF_BT2: i32 = xz_sys::LZMA_MF_BT2 as _;
     #[pyattr]
-    const MF_BT3: i32 = liblzma_sys::LZMA_MF_BT3 as _;
+    const MF_BT3: i32 = xz_sys::LZMA_MF_BT3 as _;
     #[pyattr]
-    const MF_BT4: i32 = liblzma_sys::LZMA_MF_BT4 as _;
+    const MF_BT4: i32 = xz_sys::LZMA_MF_BT4 as _;
 
     #[pyattr]
-    const MODE_FAST: i32 = liblzma_sys::LZMA_MODE_FAST as _;
+    const MODE_FAST: i32 = xz_sys::LZMA_MODE_FAST as _;
     #[pyattr]
-    const MODE_NORMAL: i32 = liblzma_sys::LZMA_MODE_NORMAL as _;
+    const MODE_NORMAL: i32 = xz_sys::LZMA_MODE_NORMAL as _;
 
     enum Format {
         Auto = 0,
@@ -385,13 +383,13 @@ mod _lzma {
         Ok(filters)
     }
 
-    const DEFAULT_LC: u32 = liblzma_sys::LZMA_LC_DEFAULT;
-    const DEFAULT_LP: u32 = liblzma_sys::LZMA_LP_DEFAULT;
-    const DEFAULT_PB: u32 = liblzma_sys::LZMA_PB_DEFAULT;
+    const DEFAULT_LC: u32 = xz_sys::LZMA_LC_DEFAULT;
+    const DEFAULT_LP: u32 = xz_sys::LZMA_LP_DEFAULT;
+    const DEFAULT_PB: u32 = xz_sys::LZMA_PB_DEFAULT;
     const DICT_POW2: [u8; 10] = [18, 20, 21, 22, 22, 23, 23, 24, 25, 26];
 
     fn preset_dict_size(preset: u32) -> u32 {
-        let level = (preset & liblzma_sys::LZMA_PRESET_LEVEL_MASK) as usize;
+        let level = (preset & xz_sys::LZMA_PRESET_LEVEL_MASK) as usize;
         if level > 9 {
             return 0;
         }
@@ -493,7 +491,7 @@ mod _lzma {
 
     #[pyfunction]
     fn is_check_supported(check_id: i32) -> bool {
-        unsafe { liblzma_sys::lzma_check_is_supported(check_id as _) != 0 }
+        unsafe { xz_sys::lzma_check_is_supported(check_id as _) != 0 }
     }
 
     #[pyfunction]