docker build --no-cache=true still builds with cache?
<p>I build an image:
Dockerfile:</p>

<pre><code>FROM centos:7
</code></pre>

<p>build command:</p>

<pre><code>$ docker build -t my-image:1.0 .
</code></pre>

<p>Now I make a second image (which is based on the original dockerfile)
Dockerfile:</p>

<pre><code>FROM centos:7
RUN yum install -y mysql
</code></pre>

<p>I build with the <code>--no-cache</code> option on true</p>

<pre><code>$ docker build --no-cache=true -t my-image:1.1 .

Sending build context to Docker daemon 2.048 kB
Step 1 : FROM centos:7
 ---&gt; 970633036444
Step 2 : xx
</code></pre>

<p>it seems to use the cache. And also when I try to delete my-image:1.0:</p>

<pre><code>docker rmi 970633036444
Error response from daemon: conflict: unable to delete 970633036444 (cannot be forced) - image has dependent child images
</code></pre>

<p>What am I doing wrong?</p>