use checkout specific commit of amalgamate repo

script/create-single-header.sh

@@ -3,7 +3,15 @@
 workingcopy_dir="$( cd -- "$( dirname -- "${BASH_SOURCE[0]:-$0}"; )" &> /dev/null && pwd 2> /dev/null; )/.."
 dst=${1:-$workingcopy_dir/single-header/include/alpaka/alpaka.hpp}
 tmp_dir=$(mktemp -d)
-git clone https://github.com/shrpnsld/amalgamate.git --depth 1 $tmp_dir/clone
+# clone amalgamate into $tmp_dir/clone and checkout to a specific commit
+current_dir=$(pwd) # Save the current directory
+commit_hash="a4796f0515fbc56d375a5013dd9004605df9c761"
+git clone https://github.com/shrpnsld/amalgamate.git --depth 1 "$tmp_dir/clone" &&
+cd "$tmp_dir/clone" &&
+git fetch --depth 1 origin "$commit_hash" &&
+git checkout "$commit_hash"
+cd "$current_dir"
+#run amalgamate command to create header file
 $tmp_dir/clone/amalgamate -o $tmp_dir -v -a -n 'alpaka' -I $workingcopy_dir/include -- $workingcopy_dir/include/alpaka/alpaka.hpp
 mv $tmp_dir/alpaka-amalgamated/alpaka.hpp $dst
 rm -rf $tmp_dir