| <p><code>List of <a href="${link build-ref#labels}">labels</a> |
| ; optional; <a href="#configurable-attributes">nonconfigurable</a></code></p> |
| |
| <p> |
| The list of environments this target can be built for, in addition to |
| default-supported environments. |
| </p> |
| |
| <p> |
| This is part of Bazel's constraint system, which lets users declare which |
| targets can and cannot depend on each other. For example, externally deployable |
| binaries shouldn't depend on libraries with company-secret code. See |
| <a href="https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/analysis/constraints/ConstraintSemantics.java#L46"> |
| ConstraintSemantics</a> for details. |
| </p> |
