diff --git a/packages/google-cloud-bigquery-datatransfer/samples/noxfile.py b/packages/google-cloud-bigquery-datatransfer/samples/noxfile.py
index ba55d7ce53ca..01686e4a0379 100644
--- a/packages/google-cloud-bigquery-datatransfer/samples/noxfile.py
+++ b/packages/google-cloud-bigquery-datatransfer/samples/noxfile.py
@@ -201,6 +201,11 @@ def _get_repo_root():
             break
         if Path(p / ".git").exists():
             return str(p)
+        # .git is not available in repos cloned via Cloud Build
+        # setup.py is always in the library's root, so use that instead
+        # https://github.com/googleapis/synthtool/issues/792
+        if Path(p / "setup.py").exists():
+            return str(p)
         p = p.parent
     raise Exception("Unable to detect repository root.")
 
diff --git a/packages/google-cloud-bigquery-datatransfer/samples/snippets/noxfile.py b/packages/google-cloud-bigquery-datatransfer/samples/snippets/noxfile.py
index ba55d7ce53ca..01686e4a0379 100644
--- a/packages/google-cloud-bigquery-datatransfer/samples/snippets/noxfile.py
+++ b/packages/google-cloud-bigquery-datatransfer/samples/snippets/noxfile.py
@@ -201,6 +201,11 @@ def _get_repo_root():
             break
         if Path(p / ".git").exists():
             return str(p)
+        # .git is not available in repos cloned via Cloud Build
+        # setup.py is always in the library's root, so use that instead
+        # https://github.com/googleapis/synthtool/issues/792
+        if Path(p / "setup.py").exists():
+            return str(p)
         p = p.parent
     raise Exception("Unable to detect repository root.")
 
diff --git a/packages/google-cloud-bigquery-datatransfer/synth.metadata b/packages/google-cloud-bigquery-datatransfer/synth.metadata
index a036d5945dea..759f6ddbe2e2 100644
--- a/packages/google-cloud-bigquery-datatransfer/synth.metadata
+++ b/packages/google-cloud-bigquery-datatransfer/synth.metadata
@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/python-bigquery-datatransfer.git",
-        "sha": "cc2b9ff311dfa6ec9d181d4c2a4c952a609f5dec"
+        "sha": "b95441140f7c86dd3e833aef0532badd6280ef48"
       }
     },
     {
@@ -19,14 +19,14 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "9b0da5204ab90bcc36f8cd4e5689eff1a54cc3e4"
+        "sha": "e0ae456852bf22f38796deb79cff30b516fde244"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "9b0da5204ab90bcc36f8cd4e5689eff1a54cc3e4"
+        "sha": "e0ae456852bf22f38796deb79cff30b516fde244"
       }
     }
   ],