Fix TPU tests on master builds (#15349)

Author: carmocca

.github/workflows/tpu-tests.yml

@@ -102,6 +102,7 @@ jobs:
         kubectl logs -f $pod_name --container=train > /tmp/full_output.txt
         grep '<?xml version="1.0" ?>' /tmp/full_output.txt  # sanity check
         csplit /tmp/full_output.txt '/<?xml version="1.0" ?>/'
+        cat xx00  # test logs
         mv xx01 coverage.xml
         exit $status_code
       shell: bash

dockers/tpu-tests/tpu_test_cases.jsonnet

@@ -29,11 +29,15 @@ local tputests = base.BaseTest {
       echo "--- Fetch the SHA's changes ---"
       git clone --single-branch --depth 1 https://github.com/Lightning-AI/lightning.git
       cd lightning
-      git fetch origin --depth 1 pull/{PR_NUMBER}/head:test/{PR_NUMBER}
-      git -c advice.detachedHead=false checkout {SHA}
-
-      echo "--- Install PL ---"
-      PACKAGE_NAME=pytorch FREEZE_REQUIREMENTS=1 pip install -e .[test]
+      if [ -n "{PR_NUMBER}" ]; then  # if PR number is not empty
+        # PR triggered it, check it out
+        git fetch origin --depth 1 pull/{PR_NUMBER}/head:test/{PR_NUMBER}
+        git -c advice.detachedHead=false checkout {SHA}
+      fi
+
+      echo "--- Install packages ---"
+      PACKAGE_NAME=lite pip install -e .[dev]
+      PACKAGE_NAME=pytorch pip install -e .[dev]
       pip list
 
       echo $KUBE_GOOGLE_CLOUD_TPU_ENDPOINTS