tensorflow: Writing a SavedModel on Windows with long file path fails

System information

• Have I written custom code: Yes, see below.
• OS Platform and Distribution: Windows 10 Enterprise 64Bit (10.0.16299)
• Mobile device: N/A
• TensorFlow installed from: Binary
• TensorFlow version: b’v1.10.0-rc1-19-g656e7a2b34’ 1.10.0
• Python version: 3.5.5
• Bazel version: N/A
• GCC/Compiler version: N/A
• CUDA/cuDNN version: N/A
• GPU model and memory: N/A
• Exact command to reproduce: Run the provided script on Windows

Describe the problem

When exporting a SavedModel to a directory with a rather long path the maximum file path length of Windows (260 chars) gets exceeded while creating temporary variable files and the process fails because it can’t find the file (See attachments for the full log):

NotFoundError (see above for traceback): Failed to create a NewWriteableFile: C:\reallylongpath\barfoobarfoobarfoobarfoobarfoobarfoo\barfoobarfoobarfoobarfoobarfoobarfoo\barfoobarfoobarfoobarfoobarfoobarfoo\barfoobarfoo\variables\variables_temp_cbd5fe79f07a4790a08e7c2adf1ed95b/part-00000-of-00001.data-00000-of-00001.tempstate12448200021531902965 : The system cannot find the path specified.

The usual workaround to prepend '\\\\?\\' to the path (like described here) doesn’t work (See attachments).

Source code / logs

Code to reproduce:

import tensorflow as tf

# Long export path (should be at least 140 chars long)
export_dir = r'C:\reallylongpath\barfoobarfoobarfoobarfoobarfoobarfoo\barfoobarfoobarfoobarfoobarfoobarfoo\barfoobarfoobarfoobarfoobarfoobarfoo\barfoobarfoo'
print('Export dir lenght: {}'.format(len(export_dir)))

# Build an easy graph with variables
x = tf.constant(2)
w = tf.Variable(3)
y = tf.multiply(x, w)

with tf.Session() as sess:
    # Initialize the variable
    sess.run(w.initializer)

    # Save as a SavedModel
    tf.saved_model.simple_save(sess,
                               export_dir,
                               inputs={'x': x },
                               outputs={'y': y })

Logs: Full log: log.txt

Full log with '\\\\?\\' prefix: log_prefix_0.txt

Full log with '\\?\' prefix: log_prefix_1.txt