Requires tools to test-pass if the corresponding submodule is updated.

If a PR intends to update a tool but its test has failed, abort the merge
regardless of current channel. This should help the tool maintainers if the
update turns out to be failing due to changes in latest master.

.travis.yml

@@ -5,7 +5,7 @@ services:
   - docker
 
 git:
-  depth: 1
+  depth: 2
   submodules: false
 
 matrix:

appveyor.yml

@@ -96,7 +96,7 @@ environment:
 matrix:
   fast_finish: true
 
-clone_depth: 1
+clone_depth: 2
 build: false
 
 install:

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"