Skip pyzstd with Python 3.14+

3.14 has builtin zstd support, so use the builtin one there.

app/exttarfile.py

@@ -1,34 +1,48 @@
 import tarfile
-from pyzstd import ZstdFile, ZstdError
 
+HAS_ZSTD = True
+try:
+    from compression import zstd
+except ImportError:
+    HAS_ZSTD = False
 
-class ExtTarFile(tarfile.TarFile):
-    """Extends TarFile to support zstandard"""
+ExtTarFile: type[tarfile.TarFile]
 
-    @classmethod
-    def zstdopen(cls, name, mode="r", fileobj=None, **kwargs):  # type: ignore
-        """Open zstd compressed tar archive"""
+if not HAS_ZSTD:
+    from pyzstd import ZstdFile, ZstdError
 
-        if mode not in ("r", "w", "x", "a"):
-            raise ValueError("mode must be 'r', 'w' or 'x' or 'a'")
+    class ZstTarFile(tarfile.TarFile):
+        """Extends TarFile to support zstandard"""
 
-        zstfileobj = None
-        try:
-            zstfileobj = ZstdFile(fileobj or name, mode)
-            if "r" in mode:
-                zstfileobj.peek(1)  # raises ZstdError if not a zstd file
-        except (ZstdError, EOFError) as e:
-            if zstfileobj is not None:
+        @classmethod
+        def zstdopen(cls, name, mode="r", fileobj=None, **kwargs):  # type: ignore
+            """Open zstd compressed tar archive"""
+
+            if mode not in ("r", "w", "x", "a"):
+                raise ValueError("mode must be 'r', 'w' or 'x' or 'a'")
+
+            zstfileobj = None
+            try:
+                zstfileobj = ZstdFile(fileobj or name, mode)
+                if "r" in mode:
+                    zstfileobj.peek(1)  # raises ZstdError if not a zstd file
+            except (ZstdError, EOFError) as e:
+                if zstfileobj is not None:
+                    zstfileobj.close()
+                raise tarfile.ReadError("not a zstd file") from e
+
+            try:
+                t = cls.taropen(name, mode, zstfileobj, **kwargs)
+            except Exception:
                 zstfileobj.close()
-            raise tarfile.ReadError("not a zstd file") from e
+                raise
 
-        try:
-            t = cls.taropen(name, mode, zstfileobj, **kwargs)
-        except Exception:
-            zstfileobj.close()
-            raise
+            t._extfileobj = False
+            return t
 
-        t._extfileobj = False
-        return t
+        OPEN_METH = {"zst": "zstdopen", **tarfile.TarFile.OPEN_METH}
 
-    OPEN_METH = {"zstd": "zstdopen", **tarfile.TarFile.OPEN_METH}
+    ExtTarFile = ZstTarFile
+else:
+    assert zstd
+    ExtTarFile = tarfile.TarFile

app/fetch/cygwin.py

@@ -3,7 +3,10 @@
 
 import asyncio
 
-import pyzstd
+try:
+    from compression import zstd
+except ImportError:
+    import pyzstd as zstd
 
 from ..appconfig import CYGWIN_METADATA_URL, REQUEST_TIMEOUT
 from ..appstate import ExtId, ExtInfo, state
@@ -63,7 +66,7 @@ async def update_cygwin_versions() -> None:
     logger.info("update cygwin info")
     logger.info(f"Loading {url!r}")
     data = await get_content_cached(url, timeout=REQUEST_TIMEOUT)
-    data = pyzstd.decompress(data)
+    data = zstd.decompress(data)
     cygwin_versions, cygwin_versions_mingw64 = await asyncio.to_thread(parse_cygwin_versions, url, data)
     state.set_ext_infos(ExtId("cygwin", "Cygwin", True, True), cygwin_versions)
     state.set_ext_infos(ExtId("cygwin-mingw64", "Cygwin-mingw64", False, True), cygwin_versions_mingw64)

pyproject.toml

@@ -17,7 +17,7 @@ dependencies = [
     "MarkupSafe>=3.0.2,<4",
     "uvicorn-worker>=0.4.0,<0.5",
     "packageurl-python>=0.17.0,<0.18",
-    "pyzstd>=0.18.0,<0.19",
+    "pyzstd>=0.18.0,<0.19; python_version < '3.14'",
     "mcp>=1.10.1,<2",
 ]
 

tests/test_exttarfile.py

@@ -25,7 +25,7 @@ def test_zst() -> None:
 
 def test_zstd_write() -> None:
     fileobj = io.BytesIO()
-    with ExtTarFile.open(fileobj=fileobj, mode='w:zstd') as tar:  # type: ignore
+    with ExtTarFile.open(fileobj=fileobj, mode='w:zst') as tar:  # type: ignore
         data = b"Hello world!"
         info = tarfile.TarInfo("test.txt")
         info.size = len(data)

uv.lock

@@ -485,7 +485,7 @@ dependencies = [
     { name = "mcp" },
     { name = "packageurl-python" },
     { name = "pydantic" },
-    { name = "pyzstd" },
+    { name = "pyzstd", marker = "python_full_version < '3.14'" },
     { name = "uvicorn" },
     { name = "uvicorn-worker" },
 ]
@@ -512,7 +512,7 @@ requires-dist = [
     { name = "mcp", specifier = ">=1.10.1,<2" },
     { name = "packageurl-python", specifier = ">=0.17.0,<0.18" },
     { name = "pydantic", specifier = ">=2.0.3,<3" },
-    { name = "pyzstd", specifier = ">=0.18.0,<0.19" },
+    { name = "pyzstd", marker = "python_full_version < '3.14'", specifier = ">=0.18.0,<0.19" },
     { name = "uvicorn", specifier = ">=0.38.0,<0.39" },
     { name = "uvicorn-worker", specifier = ">=0.4.0,<0.5" },
 ]