...

build.zig

@@ -27,11 +27,18 @@ pub fn build(b: *std.Build) void {
         .flags = &.{b.fmt("-I{s}", .{include_dir})},
     });
 
+    const target_os = target.result.os.tag;
+
     if (static_llvm) {
-        if (builtin.os.tag == .windows) {
-            // Windows: no llvm-config available; enumerate LLVM .lib files via dir command
-            const dir_cmd = b.fmt("dir /b {s}\\lib\\LLVM*.lib", .{llvm_prefix});
-            const libs_raw = std.mem.trim(u8, b.run(&.{ "cmd.exe", "/c", dir_cmd }), " \t\n\r");
+        if (target_os == .windows) {
+            // Windows target: enumerate LLVM .lib files in prefix.
+            // Use the host-appropriate command to list files.
+            const libs_raw = if (builtin.os.tag == .windows) blk: {
+                const dir_cmd = b.fmt("dir /b {s}\\lib\\LLVM*.lib", .{llvm_prefix});
+                break :blk std.mem.trim(u8, b.run(&.{ "cmd.exe", "/c", dir_cmd }), " \t\n\r");
+            } else blk: {
+                break :blk std.mem.trim(u8, b.run(&.{ "ls", lib_dir }), " \t\n\r");
+            };
             var libs_it = std.mem.tokenizeAny(u8, libs_raw, "\r\n");
             while (libs_it.next()) |filename| {
                 const trimmed = std.mem.trim(u8, filename, " \t");
@@ -52,7 +59,7 @@ pub fn build(b: *std.Build) void {
                 mod.linkSystemLibrary(syslib, .{});
             }
         } else {
-            // Unix: query llvm-config for the static libraries needed
+            // Unix target: query llvm-config for the static libraries needed
             const libs_raw = std.mem.trim(u8, b.run(&.{ llvm_config, "--libs", "--link-static" }), " \t\n\r");
             var libs_it = std.mem.tokenizeAny(u8, libs_raw, " \t\n\r");
             while (libs_it.next()) |flag| {
@@ -69,12 +76,22 @@ pub fn build(b: *std.Build) void {
                     mod.linkSystemLibrary(flag[2..], .{});
                 }
             }
+
+            // On Linux, add the multiarch system library directory so LLVM's
+            // system-lib dependencies (zstd, tinfo, xml2) are found by the linker.
+            if (builtin.os.tag == .linux) {
+                const multiarch = @tagName(builtin.cpu.arch) ++ "-linux-gnu";
+                mod.addLibraryPath(.{ .cwd_relative = "/usr/lib/" ++ multiarch });
+            }
         }
 
         // LLVM is C++ — link the C++ standard library.
-        // On Windows/MSVC, we link msvcprt directly (above) instead of
-        // link_libcpp, which tries to build libc++abi and conflicts with MSVC headers.
-        if (builtin.os.tag != .windows) {
+        // Windows/MSVC: msvcprt already linked above
+        // Linux (apt LLVM): compiled with GCC, needs libstdc++
+        // macOS (Homebrew LLVM): compiled with Clang, needs libc++
+        if (target_os == .linux) {
+            mod.linkSystemLibrary("stdc++", .{});
+        } else if (target_os != .windows) {
             mod.link_libcpp = true;
         }
     } else {