diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index a546b87..21b0766 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -1,20 +1,21 @@
-ARG SWIFT_VERSION=5.9
+ARG SWIFT_VERSION=6.1
 # Other ARG declarations must follow FROM
 FROM swift:${SWIFT_VERSION}
 
 ARG HYLO_LLVM_BUILD_TYPE=MinSizeRel
 ARG HYLO_LLVM_BUILD_RELEASE=20240303-215025
 ARG HYLO_LLVM_VERSION=17.0.6
+ARG CMAKE_VERSION=3.29.1
 
 ENV HYLO_LLVM_DOWNLOAD_URL="https://github.com/hylo-lang/llvm-build/releases/download"
 
-RUN apt install -y gnupg
-RUN apt update
-RUN apt install -y curl libzstd-dev libzstd1 lsb-release make ninja-build tar wget zstd software-properties-common python3-pip
-
-# Get a recent cmake (https://www.kitware.com//cmake-python-wheels/)
-RUN if $(/usr/bin/which cmake) ; then apt purge --auto-remove cmake ; fi
-RUN pip3 install --upgrade cmake
+# Install the dependencies for the LLVM build.
+# Note that we do cleanup in the same layer to save disk space.
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends gnupg curl libzstd-dev libzstd1 lsb-release make \
+       ninja-build tar wget zstd software-properties-common python3-pip cmake && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
 
 # Get the LLVM builds for the host architecture
 RUN <<EOT bash -ex -o pipefail
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 0222e1c..ecc82d4 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -3,16 +3,16 @@
     "build": {
         "dockerfile": "Dockerfile",
         "args": {
-            "SWIFT_VERSION" : "5.9",
+            "SWIFT_VERSION" : "6.1",
             "HYLO_LLVM_BUILD_TYPE": "${localEnv:HYLO_LLVM_BUILD_TYPE:MinSizeRel}"
-	}
+        }
     },
     "features": {
         "ghcr.io/devcontainers/features/common-utils:2": {
             "installZsh": "false",
             "username": "vscode",
-            "userUid": "1000",
-            "userGid": "1000",
+            "userUid": "1001", // 1000 is already taken by the default user in the container
+            "userGid": "1001",
             "upgradePackages": "false"
         },
         "ghcr.io/devcontainers/features/git:1": {
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2e313aa..3599952 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -18,7 +18,7 @@ on:
       - ".editorconfig"
 
 env:
-  swift-version: '5.10'
+  swift-version: '6.1'
 
 jobs:
   dev-container:
@@ -122,12 +122,14 @@ jobs:
       with:
         xcode-version: latest-stable
 
+    - name: Import Swift GPG Key (Ubuntu Only) # until fix arrives for https://github.com/SwiftyLab/setup-swift/issues/388
+      if: runner.os == 'Linux'
+      run: gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys '52BB 7E3D E28A 71BE 22EC 05FF EF80 A866 B47A 981F'
     - name: 'Set up swift (non-Windows)'
       if: ${{ runner.os != 'Windows' }}
       uses: SwiftyLab/setup-swift@latest
       with:
         swift-version: ${{ env.swift-version }}
-        cache-snapshot: false # Workaround for https://github.com/SwiftyLab/setup-swift/issues/315
 
     - uses: compnerd/gha-setup-vsdevenv@main
     - name: Set up swift (Windows)
@@ -168,7 +170,7 @@ jobs:
         -DCMAKE_BUILD_TYPE=${{ matrix.cmake_build_type }}
         -DBUILD_TESTING=YES
         -DLLVM_DIR=${{ github.workspace }}/${{ env.llvm_package_basename }}/lib/cmake/llvm
-        ${{ runner.os == 'macOS' && '-D CMAKE_Swift_COMPILER=swiftc' || '' }}
+        ${{ runner.os == 'macOS' && '-DCMAKE_Swift_COMPILER=swiftc -DCMAKE_OSX_SYSROOT=$(xcrun --show-sdk-path)' || '' }}
       working-directory: Swifty-LLVM
 
     - name: Build (CMake)
@@ -197,7 +199,7 @@ jobs:
         -DCMAKE_BUILD_TYPE=${{ matrix.cmake_build_type }}
         -DBUILD_TESTING=YES
         -DLLVM_DIR=${{ github.workspace }}/${{ env.llvm_package_basename }}/lib/cmake/llvm
-        ${{ runner.os == 'macOS' && '-D CMAKE_Swift_COMPILER=swiftc' || '' }}
+        ${{ runner.os == 'macOS' && '-DCMAKE_Swift_COMPILER=swiftc -DCMAKE_OSX_SYSROOT=$(xcrun --show-sdk-path)' || '' }}
 
         cd .xcode-build
 
@@ -205,7 +207,6 @@ jobs:
       working-directory: Swifty-LLVM
 
     - name: Build and Test via SPM
-      if: ${{ runner.os != 'Windows' || env.swift-version != '5.10' }}
       run: swift test -v ${{ matrix.swift_test_options }} -c ${{ matrix.spm_configuration }}
       working-directory: Swifty-LLVM
 
@@ -224,7 +225,7 @@ jobs:
 
     - name: Upload coverage reports to Codecov
       if: ${{ contains(matrix.swift_test_options, '--enable-code-coverage') }}
-      uses: codecov/codecov-action@v4
+      uses: codecov/codecov-action@v5
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         fail_ci_if_error: true
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 70be174..bd77993 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,7 @@
 # Standard project boilerplate
 #
 cmake_minimum_required(VERSION 3.26)
+set(CMAKE_OSX_DEPLOYMENT_TARGET 13.0)
 project(Swifty-LLVM
   VERSION 0.1.0
   DESCRIPTION "A Swifty interface for the LLVM compiler infrastructure, currently wrapping LLVM's C API."
diff --git a/Package.swift b/Package.swift
index a37f30f..bb57960 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version: 5.9
+// swift-tools-version: 6.1
 import PackageDescription
 
 
@@ -24,7 +24,7 @@ func pseudoPkgConfigText(_ package: String) -> String? {
   guard let pcp = ProcessInfo.processInfo.environment["PKG_CONFIG_PATH"] else { return nil }
 
   return pcp.split(separator: pathSeparator)
-    .lazy.compactMap({ try? String(contentsOfFile: "\($0)/\(package).pc") }).first
+    .lazy.compactMap({ try? String(contentsOfFile: "\($0)/\(package).pc", encoding: String.Encoding.utf8) }).first
 }
 
 /// Returns the un-quoted, un-escaped elements in the remainder of the
diff --git a/Sources/SwiftyLLVM/AddressSpace.swift b/Sources/SwiftyLLVM/AddressSpace.swift
index 4528b25..a5cc183 100644
--- a/Sources/SwiftyLLVM/AddressSpace.swift
+++ b/Sources/SwiftyLLVM/AddressSpace.swift
@@ -1,5 +1,5 @@
 /// Properties of a pointer expressed through the data layout.
-public struct AddressSpace: Hashable {
+public struct AddressSpace: Hashable, Sendable {
 
   /// The LLVM representation of this instance.
   public let llvm: UInt32
@@ -10,6 +10,6 @@ public struct AddressSpace: Hashable {
   }
 
   /// The default address space.
-  public static var `default` = AddressSpace(0)
+  public static let `default` = AddressSpace(0)
 
 }
diff --git a/Sources/SwiftyLLVM/Values/Constants/Intrinsic.swift b/Sources/SwiftyLLVM/Values/Constants/Intrinsic.swift
index 87c9efb..ab5a5c7 100644
--- a/Sources/SwiftyLLVM/Values/Constants/Intrinsic.swift
+++ b/Sources/SwiftyLLVM/Values/Constants/Intrinsic.swift
@@ -37,7 +37,7 @@ extension Intrinsic {
 
   /// The name of an intrinsic.
   @dynamicMemberLookup
-  public struct Name {
+  public struct Name : Sendable {
 
     /// The value of this instance.
     public let value: String
@@ -55,6 +55,6 @@ extension Intrinsic {
   }
 
   /// The prefix of all intrinsics.
-  public static var llvm = Name("llvm")
+  public static let llvm = Name("llvm")
 
 }