Give a more actionable error message when libtpu is already in use.
diff --git a/tensorflow/core/tpu/tpu_initializer_helper.cc b/tensorflow/core/tpu/tpu_initializer_helper.cc
index 7fb57a0..859f42b 100644
--- a/tensorflow/core/tpu/tpu_initializer_helper.cc
+++ b/tensorflow/core/tpu/tpu_initializer_helper.cc
@@ -91,7 +91,9 @@
// This lock is held until the process exits intentionally. The underlying
// TPU device will be held on until it quits.
if (lockf(fd, F_TLOCK, 0) != 0) {
- LOG(INFO) << "libtpu.so already in use by another process. Not "
+ LOG(INFO) << "libtpu.so already in use by another process. "
+ "Run \"$ sudo lsof -w /dev/accel0\" to figure out "
+ "which process is using the TPU. Not "
"attempting to load libtpu.so in this process.";
should_load_library = false;
} else {
