fix: use the right base branch to detect changed files

.buildkite/common.py

@@ -7,6 +7,7 @@
 
 import argparse
 import json
+import os
 import subprocess
 from pathlib import Path
 
@@ -88,11 +89,13 @@ def pipeline_to_json(pipeline):
     return json.dumps(pipeline, indent=4, sort_keys=True, ensure_ascii=False)
 
 
-def get_changed_files(branch):
+def get_changed_files():
     """
     Get all files changed since `branch`
     """
-    stdout = subprocess.check_output(["git", "diff", "--name-only", branch])
+    branch = os.environ.get("BUILDKITE_PULL_REQUEST_BASE_BRANCH", "main")
+    stdout = subprocess.check_output(f"git diff --name-only origin/{branch}".split(" "))
+
     return [Path(line) for line in stdout.decode().splitlines()]
 
 

.buildkite/pipeline_pr.py

@@ -108,7 +108,7 @@
     step["label"] = "🔍 Kani"
 
 steps = [step_style]
-changed_files = get_changed_files("main")
+changed_files = get_changed_files()
 
 # run sanity build of devtool if Dockerfile is changed
 if any(x.name == "Dockerfile" for x in changed_files):

.buildkite/pipeline_pr_no_block.py

@@ -37,6 +37,6 @@
     **defaults,
 )
 
-changed_files = get_changed_files("main")
+changed_files = get_changed_files()
 pipeline = {"steps": [optional_grp]} if run_all_tests(changed_files) else {"steps": []}
 print(pipeline_to_json(pipeline))