<p><code>List of <a href="../build-ref.html#labels">labels</a>; optional</code></p>

<p>
The list of environments this rule can be built for, <i>instead</i> of
default-supported environments.
</p>

<p>
This is part of Bazel's soft-launched constraint system. See
<code><a href="#common.compatible_with">compatible_with</a></code>
for details.
</p>
