diff --git a/README.md b/README.md
index c29433a6..d369eafc 100644
--- a/README.md
+++ b/README.md
@@ -185,7 +185,7 @@ There are a couple annoying steps you need to accomplish before building
 LLVMSwift:
 
 - Install LLVM 8.0+ using your favorite package manager. For example:
-  - `brew install llvm`
+  - `brew install llvm@11`
 - Ensure `llvm-config` is in your `PATH`
   - That will reside in the `/bin` folder wherever your package manager
     installed LLVM.
@@ -198,7 +198,7 @@ compiler projects!
 ### Installation with Swift Package Manager
 
 ```swift
-.package(url: "https://github.com/llvm-swift/LLVMSwift.git", from: "0.4.0")
+.package(url: "https://github.com/llvm-swift/LLVMSwift.git", from: "0.8.0")
 ```
 
 ### Installation without Swift Package Manager
diff --git a/Sources/LLVM/DIBuilder.swift b/Sources/LLVM/DIBuilder.swift
index b61a35b9..de36b885 100644
--- a/Sources/LLVM/DIBuilder.swift
+++ b/Sources/LLVM/DIBuilder.swift
@@ -197,6 +197,8 @@ extension DIBuilder {
   ///     by third-party tools.
   ///   - splitDWARFPath: The path to the split DWARF file.
   ///   - identity: The identity of the tool that is compiling this source file.
+  ///   - sysRoot: The Clang system root (the value of the `-isysroot` that's passed to clang).
+  ///   - sdkRoot: The SDK root -- on Darwin platforms, this is the last component of the sysroot.
   /// - Returns: A value representing a compilation-unit level scope.
   public func buildCompileUnit(
     for language: DWARFSourceLanguage,
@@ -208,7 +210,9 @@ extension DIBuilder {
     flags: [String] = [],
     runtimeVersion: Int = 0,
     splitDWARFPath: String = "",
-    identity: String = ""
+    identity: String = "",
+    sysRoot: String = "",
+    sdkRoot: String = ""
   ) -> CompileUnitMetadata {
     let allFlags = flags.joined(separator: " ")
     guard let cu = LLVMDIBuilderCreateCompileUnit(
@@ -220,7 +224,11 @@ extension DIBuilder {
       kind.llvm,
       /*DWOId*/0,
       splitDebugInlining.llvm,
-      debugInfoForProfiling.llvm
+      debugInfoForProfiling.llvm,
+      sysRoot,
+      sysRoot.count,
+      sdkRoot,
+      sdkRoot.count
     ) else {
       fatalError()
     }
@@ -860,15 +868,22 @@ extension DIBuilder {
   /// - Parameters:
   ///   - type: Original type.
   ///   - name: Typedef name.
+  ///   - alignment: Alignment of the type
   ///   - scope: The surrounding context for the typedef.
   ///   - file: File where this type is defined.
   ///   - line: Line number.
   public func buildTypedef(
-    of type: DIType, name: String, scope: DIScope, file: FileMetadata, line: Int
+    of type: DIType,
+    name: String,
+    alignment: Alignment = .one,
+    scope: DIScope,
+    file: FileMetadata,
+    line: Int
   ) -> DIType {
     guard let ty = LLVMDIBuilderCreateTypedef(
       self.llvm, type.asMetadata(), name, name.count,
-      file.asMetadata(), UInt32(line), scope.asMetadata())
+      file.asMetadata(), UInt32(line), scope.asMetadata(),
+      alignment.rawValue * 8)
     else {
       fatalError("Failed to allocate metadata")
     }
diff --git a/Sources/LLVM/MetadataAttributes.swift b/Sources/LLVM/MetadataAttributes.swift
index 2af8fc07..22e9b2d6 100644
--- a/Sources/LLVM/MetadataAttributes.swift
+++ b/Sources/LLVM/MetadataAttributes.swift
@@ -455,9 +455,6 @@ public struct DIFlags : OptionSet {
   public static let forwardDeclaration  = DIFlags(rawValue: LLVMDIFlagFwdDecl.rawValue)
   /// Denotes a block object.
   public static let appleBlock          = DIFlags(rawValue: LLVMDIFlagAppleBlock.rawValue)
-  /// Denotes the structure containing a variable captured by reference in a
-  /// block object.
-  public static let blockByrefStruct    = DIFlags(rawValue: LLVMDIFlagBlockByrefStruct.rawValue)
   /// Denotes a virtual function or dynamic dispatch.
   public static let virtual             = DIFlags(rawValue: LLVMDIFlagVirtual.rawValue)
   /// Denotes a compiler-generated declaration that may not appear in source.
diff --git a/Sources/LLVM/TargetMachine.swift b/Sources/LLVM/TargetMachine.swift
index 573e484b..6c6995c9 100644
--- a/Sources/LLVM/TargetMachine.swift
+++ b/Sources/LLVM/TargetMachine.swift
@@ -238,7 +238,7 @@ public class TargetMachine {
     }
     var err: UnsafeMutablePointer<Int8>?
     let status = path.withCString { cStr -> LLVMBool in
-      var mutable = strdup(cStr)
+      let mutable = strdup(cStr)
       defer { free(mutable) }
       return LLVMTargetMachineEmitToFile(llvm, module.llvm, mutable, type.asLLVM(), &err)
     }
diff --git a/utils/make-pkgconfig.swift b/utils/make-pkgconfig.swift
index 9ed629f5..874b184d 100644
--- a/utils/make-pkgconfig.swift
+++ b/utils/make-pkgconfig.swift
@@ -63,7 +63,7 @@ func makeFile() throws {
   }
 
   /// Ensure we have llvm-config in the PATH
-  guard let llvmConfig = which("llvm-config-9") ?? which("llvm-config") ?? brewLLVMConfig() else {
+  guard let llvmConfig = which("llvm-config-11") ?? which("llvm-config") ?? brewLLVMConfig() else {
     throw "Failed to find llvm-config. Ensure llvm-config is installed and " +
           "in your PATH"
   }
@@ -84,8 +84,8 @@ func makeFile() throws {
 
   let version = (components[0], components[1], components[2])
 
-  guard version >= (9, 0, 0) else {
-    throw "LLVMSwift requires LLVM version >=9.0.0, but you have \(versionStr)"
+  guard version >= (11, 0, 0) else {
+    throw "LLVMSwift requires LLVM version >=11.0.0, but you have \(versionStr)"
   }
 
   print("LLVM version is \(versionStr)")