Error when i compile caffe(undefined reference to `caffe::DecodeDatumNative(caffe::Datum*)')
<p>when I use commands 'sudo make all' on ubuntu14.04 I get the following error</p>

<blockquote>
<pre><code>.build_debug/tools/compute_image_mean.o: In function `main':
compute_image_mean.cpp:56:undefined reference to `caffe::DecodeDatumNative(caffe::Datum*)'
</code></pre>
</blockquote>

<p>can anybody tell me what should I do and why this would happen?</p>