[embedder] Warn dev when bootstrap script changes.

Change-Id: I40dbf153abed5f2a7da9e2a10e57b5360c40c22d
diff --git a/hooks/post-checkout b/hooks/post-checkout
index a0d557b..62367ae 100755
--- a/hooks/post-checkout
+++ b/hooks/post-checkout
@@ -8,7 +8,7 @@
 
 # Check if sdk-integration has changed.
 # If it has, the SDK version has changed for the
-# repo, and the user will likely want to shut down
+# repo, and the dev will likely want to shut down
 # things that were run using the old SDK to avoid
 # incompatibility issues between old things and the new SDK.
 sdk_folder="third_party/sdk-integration"
@@ -21,10 +21,21 @@
 fi
 
 # Check if git hooks have changed.
-# Prompt the user to install the new hooks if they have.
+# Prompt the dev to install the new hooks if they have.
 hooks_folder="hooks"
 if [[ $(git diff HEAD@{1}..HEAD@{0} -- hooks | wc -l) -gt 0 ]]; then
   echo
   echo-info "\e[33;1mhooks/\e[0m has changed. To install the new Git hooks, run:"
   echo-info '$FUCHSIA_EMBEDDER_DIR/scripts/install_hooks.sh'
 fi
+
+# Check if the bootstrap script has changed.
+# Prompt the dev to re-run the bootstrap script in case there's
+# new additional setup steps they're missing.
+bootstrap_script="scripts/bootstrap.sh"
+if [[ $(git diff HEAD@{1}..HEAD@{0} -- "${bootstrap_script}" | wc -l) -gt 0 ]]; then
+  echo
+  echo-info "\e[33;1m${bootstrap_script}\e[0m has changed."
+  echo-info "To ensure that your repository is set up correctly, you may want to re-run:"
+  echo-info '$FUCHSIA_EMBEDDER_DIR/scripts/bootstrap.sh'
+fi