diff --git a/.travis.yml b/.travis.yml
index 6a7725e01cf..d955c3ac3c3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,7 @@ services:
   - docker
 
 git:
-  depth: 1
+  depth: 2
   submodules: false
 
 matrix:
diff --git a/appveyor.yml b/appveyor.yml
index da788554049..1a186c080ce 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -96,7 +96,7 @@ environment:
 matrix:
   fast_finish: true
 
-clone_depth: 1
+clone_depth: 2
 build: false
 
 install:
diff --git a/src/ci/docker/x86_64-gnu-tools/checktools.sh b/src/ci/docker/x86_64-gnu-tools/checktools.sh
index 0d40863c092..b9268fe62ed 100755
--- a/src/ci/docker/x86_64-gnu-tools/checktools.sh
+++ b/src/ci/docker/x86_64-gnu-tools/checktools.sh
@@ -16,6 +16,7 @@ X_PY="$1"
 TOOLSTATE_FILE="$(realpath $2)"
 OS="$3"
 COMMIT="$(git rev-parse HEAD)"
+CHANGED_FILES="$(git diff --name-status HEAD HEAD^)"
 
 touch "$TOOLSTATE_FILE"
 
@@ -29,7 +30,28 @@ set -e
 
 cat "$TOOLSTATE_FILE"
 
-if [ "$RUST_RELEASE_CHANNEL" = nightly ]; then
+# If this PR is intended to update one of these tools, do not let the build pass
+# when they do not test-pass.
+for TOOL in rls rustfmt miri clippy; do
+    echo "Verifying status of $TOOL..."
+    if echo "$CHANGED_FILES" | grep -q "^M[[:blank:]]src/tools/$TOOL$"; then
+        echo "This PR updated 'src/tools/$TOOL', verifying if status is 'test-pass'..."
+        if grep -vq '"'"$TOOL"'[^"]*":"test-pass"' "$TOOLSTATE_FILE"; then
+            echo
+            echo "⚠️ We detected that this PR updated '$TOOL', but its tests failed."
+            echo
+            echo "If you do intend to update '$TOOL', please check the error messages above and"
+            echo "commit another update."
+            echo
+            echo "If you do NOT intend to update '$TOOL', please ensure you did not accidentally"
+            echo "change the submodule at 'src/tools/$TOOL'. You may ask your reviewer for the"
+            echo "proper steps."
+            exit 3
+        fi
+    fi
+done
+
+if [ "$RUST_RELEASE_CHANNEL" = nightly -a -n "${TOOLSTATE_REPO_ACCESS_TOKEN+is_set}" ]; then
     . "$(dirname $0)/repo.sh"
     MESSAGE_FILE=$(mktemp -t msg.XXXXXX)
     echo "($OS CI update)" > "$MESSAGE_FILE"