fix(ab): fix shared build location

In 0c55e10 we introduced shared builds
but that change was not effective until
467c90d at which point it broke AB
tests.

Fix commands so that AB tests work again.

Fixes: 0c55e10

Signed-off-by: Pablo Barbáchano <[email protected]>

Author: pb8o

.buildkite/common.py

@@ -202,7 +202,7 @@ def shared_build():
         ]
     revision_b = os.environ.get("REVISION_B")
     if revision_b is not None:
-        build_cmds.append(f"ln -svfT . build/{revision_b}")
+        build_cmds.append(f"ln -svfT .. build/{revision_b}")
     binary_dir = f"build_$(uname -m)_{random_str(k=8)}.tar.gz"
     build_cmds += [
         "du -sh build/*",

tools/ab_test.py

@@ -158,7 +158,8 @@ def load_data_series(report_path: Path, revision: str = None, *, reemit: bool =
 
 def collect_data(binary_dir: Path, tests: list[str]):
     """Executes the specified test using the provided firecracker binaries"""
-    revision = binary_dir.name
+    # Example binary_dir: ../build/main/build/cargo_target/x86_64-unknown-linux-musl/release
+    revision = binary_dir.parents[3].name
 
     print(f"Collecting samples with {binary_dir}")
     subprocess.run(
@@ -323,7 +324,7 @@ def ab_performance_test(
     print(commit_list.strip())
 
     def test_runner(workspace, _is_ab: bool):
-        bin_dir = ".." / get_binary("firecracker", workspace_dir=workspace).parent
+        bin_dir = get_binary("firecracker", workspace_dir=workspace).parent
         return collect_data(bin_dir, tests)
 
     return git_ab_test(