diff --git a/ci-targets.yaml b/ci-targets.yaml
index 0662bbee..7a12bddf 100644
--- a/ci-targets.yaml
+++ b/ci-targets.yaml
@@ -10,6 +10,7 @@ darwin:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -28,6 +29,7 @@ darwin:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -48,6 +50,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -67,6 +70,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - noopt
@@ -88,6 +92,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - noopt
@@ -109,6 +114,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - noopt
@@ -130,6 +136,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - noopt
@@ -151,6 +158,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - noopt
@@ -172,6 +180,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -193,6 +202,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -214,6 +224,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -235,6 +246,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug
       - pgo+lto
@@ -255,6 +267,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug+static
       - noopt+static
@@ -281,6 +294,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug+static
       - noopt+static
@@ -307,6 +321,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug+static
       - noopt+static
@@ -333,6 +348,7 @@ linux:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - debug+static
       - noopt+static
@@ -385,6 +401,7 @@ windows:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - pgo
     build_options_conditional:
@@ -402,6 +419,7 @@ windows:
       - "3.12"
       - "3.13"
       - "3.14"
+      - "3.15"
     build_options:
       - pgo
     build_options_conditional:
diff --git a/cpython-unix/Makefile b/cpython-unix/Makefile
index 577f44fd..b4618d22 100644
--- a/cpython-unix/Makefile
+++ b/cpython-unix/Makefile
@@ -6,7 +6,7 @@ BUILD := $(HERE)/build.py
 NULL :=
 SPACE := $(subst ,, )
 
-ALL_PYTHON_VERSIONS := 3.9 3.10 3.11 3.12 3.13 3.14
+ALL_PYTHON_VERSIONS := 3.9 3.10 3.11 3.12 3.13 3.14 3.15
 
 ifndef PYBUILD_TARGET_TRIPLE
     $(error PYBUILD_TARGET_TRIPLE not defined)
diff --git a/cpython-unix/build-cpython.sh b/cpython-unix/build-cpython.sh
index 7f7c4c38..32992ee5 100755
--- a/cpython-unix/build-cpython.sh
+++ b/cpython-unix/build-cpython.sh
@@ -512,9 +512,13 @@ if [ -n "${CPYTHON_OPTIMIZED}" ]; then
             patch -p1 -i "${ROOT}/patch-jit-llvm-version-3.13.patch"
         fi
 
-         if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_14}" ]]; then
+        if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_14}" && -n "${PYTHON_MEETS_MAXIMUM_VERSION_3_14}" ]]; then
             patch -p1 -i "${ROOT}/patch-jit-llvm-version-3.14.patch"
         fi
+
+        if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_15}" ]]; then
+            patch -p1 -i "${ROOT}/patch-jit-llvm-version-3.15.patch"
+        fi
     fi
 fi
 
@@ -609,10 +613,19 @@ if [ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_14}"  ]; then
     CONFIGURE_FLAGS="${CONFIGURE_FLAGS} ac_cv_func_explicit_bzero=no"
 fi
 
+# Define the base PGO profiling task, which we'll extend below with ignores
+export PROFILE_TASK='-m test --pgo'
+
 # On 3.14+ `test_strftime_y2k` fails when cross-compiling for `x86_64_v2` and `x86_64_v3` targets on
 # Linux, so we ignore it. See https://github.com/python/cpython/issues/128104
 if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_14}" && -n "${CROSS_COMPILING}" && "${PYBUILD_PLATFORM}" != macos* ]]; then
-    export PROFILE_TASK='-m test --pgo --ignore test_strftime_y2k'
+    PROFILE_TASK="${PROFILE_TASK} --ignore test_strftime_y2k"
+fi
+
+# On 3.15+ `test_json.test_recursion.TestCRecursion.test_highly_nested_objects_decoding` fails during
+# PGO due to RecursionError not being raised as expected. See https://github.com/python/cpython/issues/140125
+if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_15}" ]]; then
+    PROFILE_TASK="${PROFILE_TASK} --ignore test_json"
 fi
 
 # ./configure tries to auto-detect whether it can build 128-bit and 256-bit SIMD helpers for HACL,
diff --git a/cpython-unix/build-main.py b/cpython-unix/build-main.py
index e4276be2..366ec8cf 100755
--- a/cpython-unix/build-main.py
+++ b/cpython-unix/build-main.py
@@ -61,6 +61,7 @@ def main():
             "cpython-3.12",
             "cpython-3.13",
             "cpython-3.14",
+            "cpython-3.15",
         },
         default="cpython-3.11",
         help="Python distribution to build",
diff --git a/cpython-unix/build.py b/cpython-unix/build.py
index 662d7021..23d94602 100755
--- a/cpython-unix/build.py
+++ b/cpython-unix/build.py
@@ -393,13 +393,23 @@ def build_cpython_host(
     target_triple: str,
     build_options: list[str],
     dest_archive,
+    python_source=None,
+    entry_name=None,
 ):
     """Build binutils in the Docker image."""
-    archive = download_entry(entry, DOWNLOADS_PATH)
+    if not python_source:
+        python_version = entry["version"]
+        archive = download_entry(entry_name, DOWNLOADS_PATH)
+    else:
+        python_version = os.environ["PYBUILD_PYTHON_VERSION"]
+        archive = DOWNLOADS_PATH / ("Python-%s.tar.xz" % python_version)
+        print("Compressing %s to %s" % (python_source, archive))
+        with archive.open("wb") as fh:
+            create_tar_from_directory(
+                fh, python_source, path_prefix="Python-%s" % python_version
+            )
 
     with build_environment(client, image) as build_env:
-        python_version = DOWNLOADS[entry]["version"]
-
         build_env.install_toolchain(
             BUILD,
             host_platform,
@@ -434,7 +444,7 @@ def build_cpython_host(
 
         # Set environment variables allowing convenient testing for Python
         # version ranges.
-        for v in ("3.9", "3.10", "3.11", "3.12", "3.13", "3.14"):
+        for v in ("3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "3.15"):
             normal_version = v.replace(".", "_")
 
             if meets_python_minimum_version(python_version, v):
@@ -706,12 +716,15 @@ def build_cpython(
     """Build CPython in a Docker image'"""
     parsed_build_options = set(build_options.split("+"))
     entry_name = "cpython-%s" % version
-    entry = DOWNLOADS[entry_name]
     if not python_source:
+        entry = DOWNLOADS[entry_name]
         python_version = entry["version"]
         python_archive = download_entry(entry_name, DOWNLOADS_PATH)
     else:
+        entry = DOWNLOADS.get(entry_name, {})
         python_version = os.environ["PYBUILD_PYTHON_VERSION"]
+        entry.setdefault("licenses", ["Python-2.0", "CNRI-Python"])
+        entry.setdefault("python_tag", "cp" + "".join(version.split(".")))
         python_archive = DOWNLOADS_PATH / ("Python-%s.tar.xz" % python_version)
         print("Compressing %s to %s" % (python_source, python_archive))
         with python_archive.open("wb") as fh:
@@ -804,7 +817,7 @@ def build_cpython(
 
         # Set environment variables allowing convenient testing for Python
         # version ranges.
-        for v in ("3.9", "3.10", "3.11", "3.12", "3.13", "3.14"):
+        for v in ("3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "3.15"):
             normal_version = v.replace(".", "_")
 
             if meets_python_minimum_version(python_version, v):
@@ -1024,6 +1037,18 @@ def main():
         log_name = "%s-%s" % (action, host_platform)
     elif args.action.startswith("cpython-") and args.action.endswith("-host"):
         log_name = args.action
+    elif action.startswith("cpython-"):
+        version = (
+            os.environ["PYBUILD_PYTHON_VERSION"]
+            if python_source
+            else DOWNLOADS[action]["version"]
+        )
+        log_name = "%s-%s-%s-%s" % (
+            action,
+            version,
+            target_triple,
+            build_options,
+        )
     else:
         entry = DOWNLOADS[action]
         log_name = "%s-%s-%s-%s" % (
@@ -1229,14 +1254,21 @@ def main():
             )
 
         elif action.startswith("cpython-") and action.endswith("-host"):
+            entry_name = action[:-5]
+            if not python_source:
+                entry = DOWNLOADS[entry_name]
+            else:
+                entry = DOWNLOADS.get(entry_name, {})
             build_cpython_host(
                 client,
                 get_image(client, ROOT, BUILD, docker_image, host_platform),
-                action[:-5],
+                entry,
                 host_platform=host_platform,
                 target_triple=target_triple,
                 build_options=build_options,
                 dest_archive=dest_archive,
+                python_source=python_source,
+                entry_name=entry_name,
             )
 
         elif action in (
@@ -1246,6 +1278,7 @@ def main():
             "cpython-3.12",
             "cpython-3.13",
             "cpython-3.14",
+            "cpython-3.15",
         ):
             build_cpython(
                 settings,
diff --git a/cpython-unix/patch-jit-llvm-version-3.15.patch b/cpython-unix/patch-jit-llvm-version-3.15.patch
new file mode 100644
index 00000000..d87ac840
--- /dev/null
+++ b/cpython-unix/patch-jit-llvm-version-3.15.patch
@@ -0,0 +1,12 @@
+diff --git a/Tools/jit/_llvm.py b/Tools/jit/_llvm.py
+--- a/Tools/jit/_llvm.py
++++ b/Tools/jit/_llvm.py
+@@ -11,7 +11,7 @@
+ import _targets
+
+
+-_LLVM_VERSION = "19"
++_LLVM_VERSION = "20"
+ _EXTERNALS_LLVM_TAG = "llvm-19.1.7.0"
+
+
diff --git a/cpython-unix/targets.yml b/cpython-unix/targets.yml
index 73fe43cc..e2b018ef 100644
--- a/cpython-unix/targets.yml
+++ b/cpython-unix/targets.yml
@@ -70,6 +70,7 @@ aarch64-apple-darwin:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -166,6 +167,7 @@ aarch64-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .debian9
   needs_toolchain: true
   host_cc: clang
@@ -260,6 +262,7 @@ armv7-unknown-linux-gnueabi:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -301,6 +304,7 @@ armv7-unknown-linux-gnueabihf:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -383,6 +387,7 @@ mips-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -424,6 +429,7 @@ mipsel-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -465,6 +471,7 @@ ppc64le-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -506,6 +513,7 @@ riscv64-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross-riscv64
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -547,6 +555,7 @@ s390x-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   docker_image_suffix: .cross
   host_cc: /usr/bin/x86_64-linux-gnu-gcc
   host_cxx: /usr/bin/x86_64-linux-gnu-g++
@@ -639,6 +648,7 @@ x86_64-apple-darwin:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   apple_sdk_platform: macosx
   host_cc: clang
@@ -820,6 +830,7 @@ x86_64-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -866,6 +877,7 @@ x86_64_v2-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -913,6 +925,7 @@ x86_64_v3-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -960,6 +973,7 @@ x86_64_v4-unknown-linux-gnu:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -1007,6 +1021,7 @@ x86_64-unknown-linux-musl:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -1051,6 +1066,7 @@ x86_64_v2-unknown-linux-musl:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -1096,6 +1112,7 @@ x86_64_v3-unknown-linux-musl:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
@@ -1141,6 +1158,7 @@ x86_64_v4-unknown-linux-musl:
     - '3.12'
     - '3.13'
     - '3.14'
+    - '3.15'
   needs_toolchain: true
   host_cc: clang
   host_cxx: clang++
diff --git a/cpython-windows/build.py b/cpython-windows/build.py
index c94aa4ab..d02559e0 100644
--- a/cpython-windows/build.py
+++ b/cpython-windows/build.py
@@ -1856,6 +1856,7 @@ def main() -> None:
             "cpython-3.12",
             "cpython-3.13",
             "cpython-3.14",
+            "cpython-3.15",
         },
         default="cpython-3.11",
         help="Python distribution to build",
diff --git a/pythonbuild/buildenv.py b/pythonbuild/buildenv.py
index 4b2a0e6e..9266ad37 100644
--- a/pythonbuild/buildenv.py
+++ b/pythonbuild/buildenv.py
@@ -164,10 +164,9 @@ def copy_file(self, source: pathlib.Path, dest_path=None, dest_name=None):
     def install_toolchain_archive(
         self, build_dir, package_name, host_platform, version=None
     ):
-        entry = DOWNLOADS[package_name]
         basename = "%s-%s-%s.tar" % (
             package_name,
-            version or entry["version"],
+            version or DOWNLOADS[package_name]["version"],
             host_platform,
         )
 
diff --git a/pythonbuild/downloads.py b/pythonbuild/downloads.py
index 13023500..aa0bc99b 100644
--- a/pythonbuild/downloads.py
+++ b/pythonbuild/downloads.py
@@ -101,6 +101,15 @@
         "license_file": "LICENSE.cpython.txt",
         "python_tag": "cp314",
     },
+    "cpython-3.15": {
+        "url": "https://www.python.org/ftp/python/3.15.0/Python-3.15.0a1.tar.xz",
+        "size": 23646768,
+        "sha256": "3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4",
+        "version": "3.15.0a1",
+        "licenses": ["Python-2.0", "CNRI-Python"],
+        "license_file": "LICENSE.cpython.txt",
+        "python_tag": "cp315",
+    },
     "expat": {
         "url": "https://github.com/libexpat/libexpat/releases/download/R_2_6_3/expat-2.6.3.tar.xz",
         "size": 485600,
@@ -284,10 +293,10 @@
         "version": "0.13.1",
     },
     "pip": {
-        "url": "https://files.pythonhosted.org/packages/ef/7d/500c9ad20238fcfcb4cb9243eede163594d7020ce87bd9610c9e02771876/pip-24.3.1-py3-none-any.whl",
-        "size": 1822182,
-        "sha256": "3790624780082365f47549d032f3770eeb2b1e8bd1f7b2e02dace1afa361b4ed",
-        "version": "24.3.1",
+        "url": "https://files.pythonhosted.org/packages/b7/3f/945ef7ab14dc4f9d7f40288d2df998d1837ee0888ec3659c813487572faa/pip-25.2-py3-none-any.whl",
+        "size": 1752557,
+        "sha256": "6d67a2b4e7f14d8b31b8b52648866fa717f45a1eb70e83002f4331d07e953717",
+        "version": "25.2",
     },
     "readline": {
         # Mirrored from https://ftp.gnu.org/gnu/readline/readline-8.2.tar.gz
diff --git a/src/validation.rs b/src/validation.rs
index dbe89764..41992734 100644
--- a/src/validation.rs
+++ b/src/validation.rs
@@ -136,6 +136,8 @@ const PE_ALLOWED_LIBRARIES: &[&str] = &[
     "python313t.dll",
     "python314.dll",
     "python314t.dll",
+    "python315.dll",
+    "python315t.dll",
     "sqlite3.dll",
     "tcl86t.dll",
     "tk86t.dll",
@@ -149,6 +151,15 @@ const PE_ALLOWED_LIBRARIES_314: &[&str] = &[
     "msvcrt.dll",                        // zlib loads this library
 ];
 const PE_ALLOWED_LIBRARIES_ARM64: &[&str] = &["msvcrt.dll", "zlib1.dll"];
+const PE_ALLOWED_LIBRARIES_315: &[&str] = &[
+    // See `PE_ALLOWED_LIBRARIES_314` for zlib-related libraries
+    "zlib1.dll",
+    "api-ms-win-crt-private-l1-1-0.dll",
+    "msvcrt.dll",
+    // `_remote_debugging` loads `ntdll`
+    // See https://github.com/python/cpython/pull/138710
+    "ntdll.dll",
+];
 
 static GLIBC_MAX_VERSION_BY_TRIPLE: Lazy<HashMap<&'static str, version_compare::Version<'static>>> =
     Lazy::new(|| {
@@ -371,6 +382,26 @@ static DARWIN_ALLOWED_DYLIBS: Lazy<Vec<MachOAllowedDylib>> = Lazy::new(|| {
                 max_compatibility_version: "3.14.0".try_into().unwrap(),
                 required: false,
             },
+            MachOAllowedDylib {
+                name: "@executable_path/../lib/libpython3.15.dylib".to_string(),
+                max_compatibility_version: "3.15.0".try_into().unwrap(),
+                required: false,
+            },
+            MachOAllowedDylib {
+                name: "@executable_path/../lib/libpython3.15d.dylib".to_string(),
+                max_compatibility_version: "3.15.0".try_into().unwrap(),
+                required: false,
+            },
+            MachOAllowedDylib {
+                name: "@executable_path/../lib/libpython3.15t.dylib".to_string(),
+                max_compatibility_version: "3.15.0".try_into().unwrap(),
+                required: false,
+            },
+            MachOAllowedDylib {
+                name: "@executable_path/../lib/libpython3.15td.dylib".to_string(),
+                max_compatibility_version: "3.15.0".try_into().unwrap(),
+                required: false,
+            },
             MachOAllowedDylib {
                 name: "/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit".to_string(),
                 max_compatibility_version: "45.0.0".try_into().unwrap(),
@@ -1495,6 +1526,11 @@ fn validate_pe<'data, Pe: ImageNtHeaders>(
                         continue;
                     }
                 }
+                "3.15" => {
+                    if PE_ALLOWED_LIBRARIES_315.contains(&lib.as_str()) {
+                        continue;
+                    }
+                }
                 _ => {}
             }
 
@@ -1653,7 +1689,7 @@ fn validate_extension_modules(
         "3.13" => {
             wanted.extend(GLOBAL_EXTENSIONS_PYTHON_3_13);
         }
-        "3.14" => {
+        "3.14" | "3.15" => {
             wanted.extend(GLOBAL_EXTENSIONS_PYTHON_3_14);
         }
         _ => {
@@ -1678,7 +1714,7 @@ fn validate_extension_modules(
             wanted.extend(GLOBAL_EXTENSIONS_WINDOWS_PRE_3_13);
         }
 
-        if matches!(python_major_minor, "3.14") {
+        if matches!(python_major_minor, "3.14" | "3.15") {
             wanted.extend(GLOBAL_EXTENSIONS_WINDOWS_3_14);
         }
 
@@ -1718,7 +1754,7 @@ fn validate_extension_modules(
         wanted.insert("_testexternalinspection");
     }
 
-    if (is_linux || is_macos) && matches!(python_major_minor, "3.12" | "3.13" | "3.14") {
+    if (is_linux || is_macos) && matches!(python_major_minor, "3.12" | "3.13" | "3.14" | "3.15") {
         wanted.insert("_testsinglephase");
     }
 
@@ -1844,6 +1880,8 @@ fn validate_distribution(
         "3.13"
     } else if dist_filename.starts_with("cpython-3.14.") {
         "3.14"
+    } else if dist_filename.starts_with("cpython-3.15.") {
+        "3.15"
     } else {
         return Err(anyhow!("could not parse Python version from filename"));
     };