Bazel中的$ location扩展

我想添加$(location)扩展到rules_scalaforjvm_flags属性，在该属性中我在属性中设置了依赖项，data但失败了：
label '//src/java/com/google/devtools/build/lib:worker' in $(location) expression is not a declared prerequisite of this rule.
我在目标中的data属性上的标签上定义了依赖项，如下所示：

scala_specs2_junit_test(
    ...
    data = ["//src/java/com/google/devtools/build/lib:worker"],
    jvm_flags = ["-XX:HeapDumpPath=/some/custom/path", "-Dlocation.expanded=$(location //src/java/com/google/devtools/build/lib:worker)"],
)

我看到，当我将其添加ctx.attr.data到expand_location呼叫扩展中时，我确实不确定为什么这不是hack。是data确实是一个特例？

    location_expanded_jvm_flags = []
    for jvm_flag in jvm_flags:
        location_expanded_jvm_flags.append(ctx.expand_location(jvm_flag, ctx.attr.data))

还尝试查看java_*规则源以了解其工作原理（因为$(location)扩展支持该data属性），但是找不到相关的位置。

完整目标：

scala_specs2_junit_test(
    name = "Specs2Tests",
    srcs = ["src/main/scala/scala/test/junit/specs2/Specs2Tests.scala"],
    deps = [":JUnitCompileTimeDep"],
    size = "small",
    suffixes = ["Test"],
    data = ["//src/java/com/google/devtools/build/lib:worker"],
    jvm_flags = ["-XX:HeapDumpPath=/some/custom/path", "-Dlocation.expanded=$(location //src/java/com/google/devtools/build/lib:worker)"],
)