diff --git a/llvm/utils/release/test-release.sh b/llvm/utils/release/test-release.sh
--- a/llvm/utils/release/test-release.sh
+++ b/llvm/utils/release/test-release.sh
@@ -404,12 +404,23 @@
             ;;
     esac
 
-    if [ "$Phase" -eq "3" ]; then
-      project_list="$projects"
-    else
+    # During the first two phases, there is no need to build any of the projects
+    # except clang, since these phases are only meant to produce a bootstrapped
+    # clang compiler, capable of building the third phase.
+    if [ "$Phase" -lt "3" ]; then
       project_list="clang"
+    else
+      project_list="$projects"
     fi
-    runtime_list="$runtimes"
+    # During the first phase, there is no need to build any of the runtimes,
+    # since this phase is only meant to get a clang compiler, capable of
+    # building itself and any selected runtimes in the second phase.
+    if [ "$Phase" -lt "2" ]; then
+      runtime_list=""
+    else
+      runtime_list="$runtimes"
+    fi
+
     echo "# Using C compiler: $c_compiler"
     echo "# Using C++ compiler: $cxx_compiler"