Fix Imagequant linkage on Windows

setup.py

@@ -932,6 +932,8 @@ def build_extensions(self) -> None:
             defs.append(("HAVE_LIBZ", None))
         if feature.get("imagequant"):
             libs.append(feature.get("imagequant"))
+            if sys.platform == "win32":
+                libs.extend(["ws2_32", "userenv", "ntdll"])
             defs.append(("HAVE_LIBIMAGEQUANT", None))
         if feature.get("xcb"):
             libs.append(feature.get("xcb"))

winbuild/README.md

@@ -11,6 +11,7 @@ For more extensive info, see the [Windows build instructions](build.rst).
 * Requires Microsoft Visual Studio 2017 or newer with C++ component.
 * Requires NASM for libjpeg-turbo, a required dependency when using this script.
 * Requires CMake 3.15 or newer (available as Visual Studio component).
+* Requires Rust for libimagequant; skip it with `--no-imagequant`.
 * Tested on Windows Server 2025 and 2022 with Visual Studio 2022 Enterprise (GitHub
   Actions).
 

winbuild/build.rst

@@ -29,6 +29,9 @@ Download and install:
 
 * x86/AMD64: `Netwide Assembler (NASM) <https://www.nasm.us/pub/nasm/releasebuilds/?C=M;O=D>`_
 
+* libimagequant: `Rust <https://rustup.rs>`_
+  (optional, use ``--no-imagequant`` if not available)
+
 Any version of Visual Studio 2017 or newer should be supported,
 including Visual Studio 2017 Community, or Build Tools for Visual Studio 2019.
 

winbuild/build_prepare.py

@@ -322,15 +322,19 @@ def cmd_msbuild(
         "libs": [r"bin\*.lib"],
     },
     "libimagequant": {
-        "url": "https://github.com/ImageOptim/libimagequant/archive/{V['libimagequant']}.tar.gz",
+        "url": f"https://github.com/ImageOptim/libimagequant/archive/{V['libimagequant']}.tar.gz",
         "filename": f"libimagequant-{V['libimagequant']}.tar.gz",
         "license": "COPYRIGHT",
         "build": [
             cmd_cd("imagequant-sys"),
             "cargo build --release",
+            cmd_copy(
+                r"..\target\release\imagequant_sys.lib",
+                "imagequant.lib",
+            ),
         ],
         "headers": ["libimagequant.h"],
-        "libs": [r"..\target\release\imagequant_sys.lib"],
+        "libs": ["imagequant.lib"],
     },
     "harfbuzz": {
         "url": f"https://github.com/harfbuzz/harfbuzz/releases/download/{V['harfbuzz']}/FILENAME",