diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index 92638ee7..9a739530 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -33,6 +33,11 @@ jobs:
 #            os-name: "osx"
 #            platform: "arm64"
 #            python: "3.9"
+#            macos-target: "11.0"
+#          - os: "macos-11.0"
+#            os-name: "osx"
+#            platform: "arm64"
+#            python: "3.8"
 #            macos-target: "11.0"
     env:
       BUILD_COMMIT: HEAD
@@ -77,11 +82,17 @@ jobs:
             os-name: "osx"
           - os: "ubuntu-20.04"
             os-name: "focal"
-          - os: "macos-11.0"
-            os-name: "osx"
-            platform: "arm64"
-            python: "3.9"
-            macos-target: "11.0"
+# Disable whilst not available
+#          - os: "macos-11.0"
+#            os-name: "osx"
+#            platform: "arm64"
+#            python: "3.9"
+#            macos-target: "11.0"
+#          - os: "macos-11.0"
+#            os-name: "osx"
+#            platform: "arm64"
+#            python: "3.8"
+#            macos-target: "11.0"
     env:
       BUILD_COMMIT: master
       PLAT: ${{ matrix.platform }}
diff --git a/config.sh b/config.sh
index 2e2a35d2..a4e36eb0 100644
--- a/config.sh
+++ b/config.sh
@@ -28,7 +28,14 @@ function untar {
         gz|tgz) tar -zxf $in_fname ;;
         bz2) tar -jxf $in_fname ;;
         zip) unzip -qq $in_fname ;;
-        xz) unxz -c $in_fname | tar -xf - ;;
+        xz) if [ -n "$IS_MACOS" ]; then
+              tar -xf $in_fname
+            else
+              if [[ ! $(type -P "unxz") ]]; then
+                echo xz must be installed to uncompress file; exit 1
+              fi
+              unxz -c $in_fname | tar -xf -
+            fi ;;
         *) echo Did not recognize extension $extension; exit 1 ;;
     esac
 }
diff --git a/multibuild b/multibuild
index 63c1418e..125a047d 160000
--- a/multibuild
+++ b/multibuild
@@ -1 +1 @@
-Subproject commit 63c1418ea5236f2586007c5397dab1d99d4cf1dd
+Subproject commit 125a047dfd81f6d22815f91cae8cdef1f81f02ac