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

<p>
A list of
<code><a href="platform.html#constraint_value">constraint_value</a></code>s
that must be present in the target platform for this target to be considered
"compatible". This is in addition to any constraints already set by the rule
type. If the target platform does not satisfy all listed constraints then the
target is considered "incompatible". Incompatible targets are skipped for
building and testing when the target pattern is expanded
(e.g. `//...`, `:all`). When explicitly specified on the command line,
incompatible targets cause Bazel to print an error and cause a build or test
failure.
</p>

<p>
Targets that transitively depend on incompatible targets are themselves
considered incompatible. They are also skipped for building and testing.
</p>

<p>
An empty list (which is the default) signifies that the target is compatible
with all platforms.
<p>

<p>
See the <a href="../platforms.html#skipping-incompatible-targets">Platforms</a>
page for more information about incompatible target skipping.
</p>
