pub fn assert_wprof_pb_shape(path: &Path) -> Result<()>Expand description
Verify the wprof .pb at path exists, is at least
WPROF_PB_MIN_BYTES bytes, and leads with
PERFETTO_TRACE_PACKETS_TAG.
Returns Err(_) with a diagnostic naming the specific
regression hop (missing file, truncated, wrong format) so a
debugging operator can trace the failure back to the transport
site that broke. The error message references the host-side
write site at test_support::eval for missing-file diagnoses.
Intended use: a #[ktstr_test(post_vm = my_check)] callback
resolves the per-test .wprof.pb path via
VmResult::wprof_pb_path
and forwards the Result from this helper. The
VmResult::assert_wprof_pb_landed
method packages the common path-derive + shape-check into a
single call. Do NOT call from inside the guest test body —
the guest cannot read the host sidecar directory (see the
module-level doc).