diff --git a/gnu/packages/patches/zig-disable-libc-note-test.patch b/gnu/packages/patches/zig-disable-libc-note-test.patch
index 4d76139efb..b2c57cb571 100644
--- a/gnu/packages/patches/zig-disable-libc-note-test.patch
+++ b/gnu/packages/patches/zig-disable-libc-note-test.patch
@@ -1,14 +1,12 @@
-This test fails with "error.CompilationIncorrectlySucceeded".
-
 diff --git a/test/compile_errors.zig b/test/compile_errors.zig
-index fd1255c..20d5548 100644
+index b1eaa0302..621f9db0a 100644
 --- a/test/compile_errors.zig
 +++ b/test/compile_errors.zig
-@@ -2751,15 +2751,15 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
+@@ -2943,15 +2943,15 @@ pub fn addCases(ctx: *TestContext) !void {
              "tmp.zig:3:5: error: dependency on libc must be explicitly specified in the build command",
          });
-
--        cases.addTest("libc headers note",
+ 
+-        ctx.testErrStage1("libc headers note",
 -            \\const c = @cImport(@cInclude("stdio.h"));
 -            \\export fn entry() void {
 -            \\    _ = c.printf("hello, world!\n");
@@ -17,15 +15,15 @@ index fd1255c..20d5548 100644
 -            "tmp.zig:1:11: error: C import failed",
 -            "tmp.zig:1:11: note: libc headers not available; compilation does not link against libc",
 -        });
-+//        cases.addTest("libc headers note",
-+//            \\const c = @cImport(@cInclude("stdio.h"));
-+//            \\export fn entry() void {
-+//            \\    _ = c.printf("hello, world!\n");
-+//            \\}
-+//        , &[_][]const u8{
-+//            "tmp.zig:1:11: error: C import failed",
-+//            "tmp.zig:1:11: note: libc headers not available; compilation does not link against libc",
-+//        });
++        // ctx.testErrStage1("libc headers note",
++        //     \\const c = @cImport(@cInclude("stdio.h"));
++        //     \\export fn entry() void {
++        //     \\    _ = c.printf("hello, world!\n");
++        //     \\}
++        // , &[_][]const u8{
++        //     "tmp.zig:1:11: error: C import failed",
++        //     "tmp.zig:1:11: note: libc headers not available; compilation does not link against libc",
++        // });
      }
-
-     cases.addTest("comptime vector overflow shows the index",
+ 
+     ctx.testErrStage1("comptime vector overflow shows the index",
diff --git a/gnu/packages/patches/zig-use-system-paths.patch b/gnu/packages/patches/zig-use-system-paths.patch
index 33b7da1e0d..0a3cbb0e92 100644
--- a/gnu/packages/patches/zig-use-system-paths.patch
+++ b/gnu/packages/patches/zig-use-system-paths.patch
@@ -1,143 +1,144 @@
-This patch replaces the OS-specific detection mechanism by one that solely
-relies on environment variables.  This has the benefit that said environment
-variables can be used as search paths in Guix.
-
-Index: zig-0.8.1/lib/std/zig/system.zig
-===================================================================
---- zig-0.8.1.orig/lib/std/zig/system.zig
-+++ zig-0.8.1/lib/std/zig/system.zig
-@@ -39,101 +39,57 @@ pub const NativePaths = struct {
-         };
-         errdefer self.deinit();
-
--        var is_nix = false;
--        if (process.getEnvVarOwned(allocator, "NIX_CFLAGS_COMPILE")) |nix_cflags_compile| {
--            defer allocator.free(nix_cflags_compile);
+diff --git a/lib/std/zig/system/NativePaths.zig b/lib/std/zig/system/NativePaths.zig
+index 8e3e46e48..1ed9d3206 100644
+--- a/lib/std/zig/system/NativePaths.zig
++++ b/lib/std/zig/system/NativePaths.zig
+@@ -26,73 +26,42 @@ pub fn detect(allocator: Allocator, native_info: NativeTargetInfo) !NativePaths
+     };
+     errdefer self.deinit();
+ 
+-    var is_nix = false;
+-    if (process.getEnvVarOwned(allocator, "NIX_CFLAGS_COMPILE")) |nix_cflags_compile| {
+-        defer allocator.free(nix_cflags_compile);
 -
--            is_nix = true;
--            var it = mem.tokenize(nix_cflags_compile, " ");
-+        // TODO: Support cross-compile paths?
-+        if (process.getEnvVarOwned(allocator, "C_INCLUDE_PATH")) |c_include_path| {
-+            defer allocator.free(c_include_path);
-+            var it = mem.tokenize(c_include_path, ":");
-             while (true) {
--                const word = it.next() orelse break;
--                if (mem.eql(u8, word, "-isystem")) {
--                    const include_path = it.next() orelse {
--                        try self.addWarning("Expected argument after -isystem in NIX_CFLAGS_COMPILE");
--                        break;
--                    };
--                    try self.addIncludeDir(include_path);
--                } else {
--                    if (mem.startsWith(u8, word, "-frandom-seed=")) {
--                        continue;
--                    }
--                    try self.addWarningFmt("Unrecognized C flag from NIX_CFLAGS_COMPILE: {s}", .{word});
+-        is_nix = true;
+-        var it = mem.tokenize(u8, nix_cflags_compile, " ");
++    // TODO: Support cross-compile paths?
++    if (process.getEnvVarOwned(allocator, "C_INCLUDE_PATH")) |c_include_path| {
++        defer allocator.free(c_include_path);
++        var it = mem.tokenize(u8, c_include_path, ":");
+         while (true) {
+-            const word = it.next() orelse break;
+-            if (mem.eql(u8, word, "-isystem")) {
+-                const include_path = it.next() orelse {
+-                    try self.addWarning("Expected argument after -isystem in NIX_CFLAGS_COMPILE");
+-                    break;
+-                };
+-                try self.addIncludeDir(include_path);
+-            } else {
+-                if (mem.startsWith(u8, word, "-frandom-seed=")) {
+-                    continue;
 -                }
-+                const dir = it.next() orelse break;
-+                try self.addIncludeDir(dir);
-             }
-         } else |err| switch (err) {
-             error.InvalidUtf8 => {},
-             error.EnvironmentVariableNotFound => {},
-             error.OutOfMemory => |e| return e,
+-                try self.addWarningFmt("Unrecognized C flag from NIX_CFLAGS_COMPILE: {s}", .{word});
+-            }
++            const dir = it.next() orelse break;
++            try self.addIncludeDir(dir);
          }
--        if (process.getEnvVarOwned(allocator, "NIX_LDFLAGS")) |nix_ldflags| {
--            defer allocator.free(nix_ldflags);
-
--            is_nix = true;
--            var it = mem.tokenize(nix_ldflags, " ");
-+        if (process.getEnvVarOwned(allocator, "CPLUS_INCLUDE_PATH")) |cplus_include_path| {
-+            defer allocator.free(cplus_include_path);
-+            var it = mem.tokenize(cplus_include_path, ":");
-             while (true) {
--                const word = it.next() orelse break;
--                if (mem.eql(u8, word, "-rpath")) {
--                    const rpath = it.next() orelse {
--                        try self.addWarning("Expected argument after -rpath in NIX_LDFLAGS");
--                        break;
--                    };
--                    try self.addRPath(rpath);
--                } else if (word.len > 2 and word[0] == '-' and word[1] == 'L') {
--                    const lib_path = word[2..];
--                    try self.addLibDir(lib_path);
--                } else {
--                    try self.addWarningFmt("Unrecognized C flag from NIX_LDFLAGS: {s}", .{word});
+     } else |err| switch (err) {
+         error.InvalidUtf8 => {},
+         error.EnvironmentVariableNotFound => {},
+         error.OutOfMemory => |e| return e,
+     }
+-    if (process.getEnvVarOwned(allocator, "NIX_LDFLAGS")) |nix_ldflags| {
+-        defer allocator.free(nix_ldflags);
+-
+-        is_nix = true;
+-        var it = mem.tokenize(u8, nix_ldflags, " ");
++    if (process.getEnvVarOwned(allocator, "CPLUS_INCLUDE_PATH")) |cplus_include_path| {
++        defer allocator.free(cplus_include_path);
++        var it = mem.tokenize(u8, cplus_include_path, ":");
+         while (true) {
+-            const word = it.next() orelse break;
+-            if (mem.eql(u8, word, "-rpath")) {
+-                const rpath = it.next() orelse {
+-                    try self.addWarning("Expected argument after -rpath in NIX_LDFLAGS");
 -                    break;
--                }
-+                const dir = it.next() orelse break;
-+                try self.addIncludeDir(dir);
-             }
-         } else |err| switch (err) {
-             error.InvalidUtf8 => {},
-             error.EnvironmentVariableNotFound => {},
-             error.OutOfMemory => |e| return e,
+-                };
+-                try self.addRPath(rpath);
+-            } else if (word.len > 2 and word[0] == '-' and word[1] == 'L') {
+-                const lib_path = word[2..];
+-                try self.addLibDir(lib_path);
+-            } else {
+-                try self.addWarningFmt("Unrecognized C flag from NIX_LDFLAGS: {s}", .{word});
+-                break;
+-            }
++            const dir = it.next() orelse break;
++            try self.addIncludeDir(dir);
          }
--        if (is_nix) {
--            return self;
--        }
+     } else |err| switch (err) {
+         error.InvalidUtf8 => {},
+         error.EnvironmentVariableNotFound => {},
+         error.OutOfMemory => |e| return e,
+     }
+-    if (is_nix) {
+-        return self;
+-    }
 -
--        if (comptime Target.current.isDarwin()) {
--            try self.addIncludeDir("/usr/include");
--            try self.addIncludeDir("/usr/local/include");
-
--            try self.addLibDir("/usr/lib");
--            try self.addLibDir("/usr/local/lib");
+-    if (comptime builtin.target.isDarwin()) {
+-        try self.addIncludeDir("/usr/include");
+-        try self.addIncludeDir("/usr/local/include");
 -
--            try self.addFrameworkDir("/Library/Frameworks");
--            try self.addFrameworkDir("/System/Library/Frameworks");
+-        try self.addLibDir("/usr/lib");
+-        try self.addLibDir("/usr/local/lib");
 -
--            return self;
-+        if (process.getEnvVarOwned(allocator, "LIBRARY_PATH")) |library_path| {
-+            defer allocator.free(library_path);
-+            var it = mem.tokenize(library_path, ":");
-+            while (true) {
-+                const dir = it.next() orelse break;
-+                try self.addLibDir(dir);
-+            }
-+        } else |err| switch (err) {
-+            error.InvalidUtf8 => {},
-+            error.EnvironmentVariableNotFound => {},
-+            error.OutOfMemory => |e| return e,
-         }
-
--        if (native_target.os.tag != .windows) {
--            const triple = try native_target.linuxTriple(allocator);
--            const qual = native_target.cpu.arch.ptrBitWidth();
+-        try self.addFrameworkDir("/Library/Frameworks");
+-        try self.addFrameworkDir("/System/Library/Frameworks");
 -
--            // TODO: $ ld --verbose | grep SEARCH_DIR
--            // the output contains some paths that end with lib64, maybe include them too?
--            // TODO: what is the best possible order of things?
--            // TODO: some of these are suspect and should only be added on some systems. audit needed.
+-        return self;
++    if (process.getEnvVarOwned(allocator, "LIBRARY_PATH")) |library_path| {
++        defer allocator.free(library_path);
++        var it = mem.tokenize(u8, library_path, ":");
++        while (true) {
++            const dir = it.next() orelse break;
++            try self.addLibDir(dir);
++        }
++    } else |err| switch (err) {
++        error.InvalidUtf8 => {},
++        error.EnvironmentVariableNotFound => {},
++        error.OutOfMemory => |e| return e,
+     }
+ 
+     if (comptime native_target.os.tag == .solaris) {
+@@ -106,32 +75,17 @@ pub fn detect(allocator: Allocator, native_info: NativeTargetInfo) !NativePaths
+         return self;
+     }
+ 
+-    if (native_target.os.tag != .windows) {
+-        const triple = try native_target.linuxTriple(allocator);
+-        const qual = native_target.cpu.arch.ptrBitWidth();
 -
--            try self.addIncludeDir("/usr/local/include");
--            try self.addLibDirFmt("/usr/local/lib{d}", .{qual});
--            try self.addLibDir("/usr/local/lib");
+-        // TODO: $ ld --verbose | grep SEARCH_DIR
+-        // the output contains some paths that end with lib64, maybe include them too?
+-        // TODO: what is the best possible order of things?
+-        // TODO: some of these are suspect and should only be added on some systems. audit needed.
 -
--            try self.addIncludeDirFmt("/usr/include/{s}", .{triple});
--            try self.addLibDirFmt("/usr/lib/{s}", .{triple});
+-        try self.addIncludeDir("/usr/local/include");
+-        try self.addLibDirFmt("/usr/local/lib{d}", .{qual});
+-        try self.addLibDir("/usr/local/lib");
 -
--            try self.addIncludeDir("/usr/include");
--            try self.addLibDirFmt("/lib{d}", .{qual});
--            try self.addLibDir("/lib");
--            try self.addLibDirFmt("/usr/lib{d}", .{qual});
--            try self.addLibDir("/usr/lib");
+-        try self.addIncludeDirFmt("/usr/include/{s}", .{triple});
+-        try self.addLibDirFmt("/usr/lib/{s}", .{triple});
 -
--            // example: on a 64-bit debian-based linux distro, with zlib installed from apt:
--            // zlib.h is in /usr/include (added above)
--            // libz.so.1 is in /lib/x86_64-linux-gnu (added here)
--            try self.addLibDirFmt("/lib/{s}", .{triple});
-+        if (process.getEnvVarOwned(allocator, "DYLD_FRAMEWORK_PATH")) |dyld_framework_path| {
-+            defer allocator.free(dyld_framework_path);
-+            var it = mem.tokenize(dyld_framework_path, ":");
-+            while (true) {
-+                const dir = it.next() orelse break;
-+                try self.addFrameworkDir(dir);
-+            }
-+        } else |err| switch (err) {
-+            error.InvalidUtf8 => {},
-+            error.EnvironmentVariableNotFound => {},
-+            error.OutOfMemory => |e| return e,
-         }
-
-         return self;
+-        try self.addIncludeDir("/usr/include");
+-        try self.addLibDirFmt("/lib{d}", .{qual});
+-        try self.addLibDir("/lib");
+-        try self.addLibDirFmt("/usr/lib{d}", .{qual});
+-        try self.addLibDir("/usr/lib");
+-
+-        // example: on a 64-bit debian-based linux distro, with zlib installed from apt:
+-        // zlib.h is in /usr/include (added above)
+-        // libz.so.1 is in /lib/x86_64-linux-gnu (added here)
+-        try self.addLibDirFmt("/lib/{s}", .{triple});
++    if (process.getEnvVarOwned(allocator, "DYLD_FRAMEWORK_PATH")) |dyld_framework_path| {
++        defer allocator.free(dyld_framework_path);
++        var it = mem.tokenize(u8, dyld_framework_path, ":");
++        while (true) {
++            const dir = it.next() orelse break;
++            try self.addFrameworkDir(dir);
++        }
++    } else |err| switch (err) {
++        error.InvalidUtf8 => {},
++        error.EnvironmentVariableNotFound => {},
++        error.OutOfMemory => |e| return e,
+     }
+ 
+     return self;
diff --git a/gnu/packages/zig.scm b/gnu/packages/zig.scm
index 9cd869389b..b3de72226b 100644
--- a/gnu/packages/zig.scm
+++ b/gnu/packages/zig.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2021 Liliana Marie Prikler <liliana.prikler@gmail.com>
 ;;; Copyright © 2021 Sarah Morgensen <iskarian@mgsn.dev>
+;;; Copyright © 2021 Calum Irwin <calumirwin1@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -28,7 +29,7 @@ (define-module (gnu packages zig)
 (define-public zig
   (package
     (name "zig")
-    (version "0.8.1")
+    (version "0.9.0")
     (source
      (origin
        (method git-fetch)
@@ -37,18 +38,18 @@ (define-public zig
              (commit version)))
        (file-name (git-file-name name version))
        (sha256
-        (base32 "147qx7xgj0r353wh5ragzn6kmm1vrf31i8038z3zqwjnqqgqxi6c"))
+        (base32 "1zdz5s434c48z3y0c8l9wm2z1gxa7yyzd53zmr68lwj6mcl7by8x"))
        (patches
         (search-patches
          "zig-disable-libc-note-test.patch"
          "zig-use-system-paths.patch"))))
     (build-system cmake-build-system)
     (inputs
-     (list clang-12 ; Clang propagates llvm.
-           lld-12))
+     (list clang-13 ; Clang propagates llvm.
+           lld))
     ;; Zig compiles fine with GCC, but also needs native LLVM libraries.
     (native-inputs
-     (list llvm-12))
+     (list llvm-13))
     (arguments
      `(#:configure-flags
        (list ,@(if (%current-target-system)
