diff --git a/.github/workflows/test_and_build.yml b/.github/workflows/test_and_build.yml
index 8d575a1..de80c69 100644
--- a/.github/workflows/test_and_build.yml
+++ b/.github/workflows/test_and_build.yml
@@ -80,15 +80,19 @@ jobs:
               run: |
                   # Build package
                   
-
                   if [[ "${{matrix.os}}" == "ubuntu-latest" ]]; then
                   
-                  conda install -c conda-forge boa -n base
-                  conda mambabuild --no-build-id --python=${{matrix.python-version}} conda_recipe/xspec-modelsonly-linux
+                  #conda install -c conda-forge boa -n base
+                  #conda mambabuild --no-build-id --python=${{matrix.python-version}} conda_recipe/xspec-modelsonly-linux
+                  conda build --no-build-id --python=${{matrix.python-version}} conda_recipe/xspec-modelsonly-linux
 
                   else
-
-                  conda install -c conda-forge clang_osx-64 clangxx_osx-64 gfortran_osx-64
+                  curl -LO -z MacOSX10.9.sdk.tar.xz https://github.com/phracker/MacOSX-SDKs/releases/download/10.13/MacOSX10.9.sdk.tar.xz
+                  if [[ $? -ne 0 ]]; then
+                  echo "macOS 10.9 SDK download failed"
+                  fi
+                  tar -C /opt/SDK/10.9SDK -xf MacOSX10.9.sdk.tar.xz
+                  #conda install -c conda-forge clang_osx-64 clangxx_osx-64 gfortran_osx-64
                   conda build --python=${{matrix.python-version}} conda_recipe/xspec-modelsonly
 
                   fi
diff --git a/build_local.sh b/build_local.sh
index 1ee63dc..4be50a0 100755
--- a/build_local.sh
+++ b/build_local.sh
@@ -13,6 +13,7 @@ if [[ "$OSTYPE" == "linux-gnu" ]]; then
 
         TRAVIS_OS_NAME="linux"
 
+        #compilers="gcc_linux-64 gxx_linux-64 gfortran_linux-64"
 
 elif [[ "$OSTYPE" == darwin* ]]; then
 
@@ -20,7 +21,13 @@ elif [[ "$OSTYPE" == darwin* ]]; then
 
         TRAVIS_OS_NAME="osx"
 
-
+        #compilers="clang_osx-64 clangxx_osx-64 gfortran_osx-64"
+        #Download the macOS 10.9 SDK to the CONDA_BUILD_SYSROOT location for the Conda Compilers to work
+        curl -LO -z MacOSX10.9.sdk.tar.xz https://github.com/phracker/MacOSX-SDKs/releases/download/10.13/MacOSX10.9.sdk.tar.xz
+        if [[ $? -ne 0 ]]; then
+        echo "macOS 10.9 SDK download failed"
+        fi
+        tar -C /opt/SDK/10.9SDK -xf MacOSX10.9.sdk.tar.xz
 elif [[ "$OSTYPE" == "cygwin" ]]; then
 
         # POSIX compatibility layer and Linux environment emulation for Windows
@@ -86,18 +93,20 @@ if ! [ -f heasoft-6.30.1src.tar.gz ]; then
 fi
 
 # Build package
-echo "Build package..."
+echo "======> Build package..."
 
 #conda install conda-verify
 
-conda install -c conda-forge boa -n base
+#conda install -c conda-forge boa -n base
 
 if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
-    conda mambabuild --python=$TRAVIS_PYTHON_VERSION conda_recipe/xspec-modelsonly
+    #conda mambabuild --python=$TRAVIS_PYTHON_VERSION conda_recipe/xspec-modelsonly
+    conda build --python=$TRAVIS_PYTHON_VERSION conda_recipe/xspec-modelsonly
     #conda index $HOME/miniconda/conda-bld
 else
     # there is some strange error about the prefix length
-    conda mambabuild --no-build-id --python=$TRAVIS_PYTHON_VERSION conda_recipe/xspec-modelsonly
+    #conda mambabuild --no-build-id --python=$TRAVIS_PYTHON_VERSION conda_recipe/xspec-modelsonly
+    conda build --no-build-id --python=$TRAVIS_PYTHON_VERSION conda_recipe/xspec-modelsonly
     #conda index $HOME/miniconda/conda-bld
 fi
 echo "======> installing..."
diff --git a/conda_recipe/xspec-modelsonly/build.sh b/conda_recipe/xspec-modelsonly/build.sh
index e2f6949..221da5f 100644
--- a/conda_recipe/xspec-modelsonly/build.sh
+++ b/conda_recipe/xspec-modelsonly/build.sh
@@ -1,4 +1,4 @@
-echo "================="
+echo "================= build.sh =================="
 echo $PWD
 echo $RECIPE_DIR
 echo $CC
diff --git a/conda_recipe/xspec-modelsonly/conda_build_config.yaml b/conda_recipe/xspec-modelsonly/conda_build_config.yaml
index 341b44b..ecd8cce 100644
--- a/conda_recipe/xspec-modelsonly/conda_build_config.yaml
+++ b/conda_recipe/xspec-modelsonly/conda_build_config.yaml
@@ -4,5 +4,7 @@ c_compiler:
 cxx_compiler:
   - gxx # [linux]
   - clangxx # [osx]
+fortran_compiler:
+  - gfortran # [osx]
 CONDA_BUILD_SYSROOT:
-  - /opt/MacOSX10.10.sdk  # [osx]
+  - /opt/SDK/10.9SDK/MacOSX10.9.sdk  # [osx]