diff --git a/.github/workflows/onpullrequest-build-ubuntu.yml b/.github/workflows/onpullrequest-build-ubuntu.yml
index e5af31eb5..829d4ebed 100644
--- a/.github/workflows/onpullrequest-build-ubuntu.yml
+++ b/.github/workflows/onpullrequest-build-ubuntu.yml
@@ -19,7 +19,7 @@ jobs:
     - name: Cache grpc
       uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     - name: Build grpc
       run: if ! [ -d depends/grpc ] ; then scripts/install_grpc /usr v1.31.x depends/grpc ; fi
@@ -54,12 +54,12 @@ jobs:
     - name: Cache grpc
       uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     - name: Cache ccache
       uses: actions/cache@v2
       with:
-        key: prover-tests-ccache-${{ needs.onpr-submodules.outputs.commits }}-${{ matrix.curve }}-${{ runner.os }}-test
+        key: prover-tests-ccache-${{ needs.onpr-submodules.outputs.commits }}-${{ matrix.curve }}-${{ runner.os }}
         path: ~/.ccache
     - name: Cache pip
       uses: actions/cache@v2
@@ -99,14 +99,14 @@ jobs:
     - name: Cache grpc
       uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     # ccache in this job seems to make the tests crash occasionally. Disabling
     # until the cause is understood.
     # - name: Cache ccache
     #   uses: actions/cache@v2
     #   with:
-    #     key: integration-tests-ccache-${{ needs.onpr-submodules.outputs.commits }}-${{ matrix.curve }}-${{ runner.os }}-test
+    #     key: integration-tests-ccache-${{ needs.onpr-submodules.outputs.commits }}-${{ matrix.curve }}-${{ runner.os }}
     #     path: ~/.ccache
     - name: Cache pip
       uses: actions/cache@v2
diff --git a/.github/workflows/onpush-build-macos.yml b/.github/workflows/onpush-build-macos.yml
index 02c5107ef..7b86fd776 100644
--- a/.github/workflows/onpush-build-macos.yml
+++ b/.github/workflows/onpush-build-macos.yml
@@ -34,7 +34,7 @@ jobs:
       with:
         submodules: recursive
     - name: Cache ccache
-      uses: actions/cache@v1
+      uses: actions/cache@v2
       with:
         key: submodules-${{ needs.submodules.outputs.commits }}-${{ runner.os }}-${{ matrix.config }}
         path: ~/Library/Caches/ccache
diff --git a/.github/workflows/onpush-build-ubuntu.yml b/.github/workflows/onpush-build-ubuntu.yml
index 158971460..1c711ff8a 100644
--- a/.github/workflows/onpush-build-ubuntu.yml
+++ b/.github/workflows/onpush-build-ubuntu.yml
@@ -19,7 +19,7 @@ jobs:
     - name: Cache grpc
       uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     - name: Build grpc
       run: if ! [ -d depends/grpc ] ; then scripts/install_grpc /usr v1.31.x depends/grpc ; fi
@@ -37,7 +37,7 @@ jobs:
     - name: Cache grpc
       uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     - name: Cache pip (for mpc tests)
       uses: actions/cache@v2
@@ -59,9 +59,9 @@ jobs:
       with:
         submodules: recursive
     - name: Cache grpc
-      uses: actions/cache@v1
+      uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     - name: Install dependencies
       run: |
@@ -80,7 +80,7 @@ jobs:
     - name: Cache grpc
       uses: actions/cache@v2
       with:
-        key: grpc-1.31.x-${{ runner.os }}-test
+        key: grpc-1.31.x-${{ runner.os }}
         path: depends/grpc
     - name: Install dependencies
       run: |
diff --git a/scripts/install_grpc b/scripts/install_grpc
index 085ba1e75..1dfbcffe8 100755
--- a/scripts/install_grpc
+++ b/scripts/install_grpc
@@ -3,7 +3,8 @@
 # This script is only intended to run on the CI machines. Not for local
 # development.
 
-if [ "" == "$1" ] || [ "" == "$2" ] || [ "" == "$3" ] ; then
+# Expect 3 arguments, all non-empty.
+if [ "$#" -ne 3 ] || [ "" == "$1" ] || [ "" == "$2" ] || [ "" == "$3" ] ; then
    echo "error: invalid arguments"
    echo "Usage: $0 <install-location> <version> <build-dir>"
    echo ""
@@ -34,14 +35,14 @@ mkdir -p ${BUILD_DIR}
 pushd ${BUILD_DIR}
 
     # Clone repo and submodules (if DO_BUILD == 1)
-    if [ "1" == "${DO_BUILD}" ] ; then
+    if [ "${DO_BUILD}" == "1" ] ; then
         git clone --depth 1 -b ${VERSION} https://github.com/grpc/grpc .
         git submodule update --depth 1 --init --recursive
     fi
 
     # Install protobuf
     pushd third_party/protobuf
-        if [ "1" == "${DO_BUILD}" ] ; then
+        if [ "${DO_BUILD}" == "1" ] ; then
             [ -e ./configure ] || ./autogen.sh
             DIST_LANG=cpp ./configure --prefix ${INSTALL_DIR}
             make -j $(($(nproc)+1))
@@ -52,7 +53,7 @@ pushd ${BUILD_DIR}
     # Install grpc
     mkdir -p build
     pushd build
-        if [ "1" == "${DO_BUILD}" ] ; then
+        if [ "${DO_BUILD}" == "1" ] ; then
             cmake \
                 -DCMAKE_PREFIX_PATH=${INSTALL_DIR}       \
                 -DCMAKE_INSTALL_PREFIX=${INSTALL_DIR}    \