How to correctly use `strictly` with gradle

In gradle 6.7.1 I am trying to use strictly to specify a range of versions for a transitive dependency.

In the documentation linked above, it says

For example, [...] instead of strictly 1.0, that it strictly depends on the [1.0, 2.0[ range, but prefers 1.0.

I am trying what was suggested, where I want to specify a range with a minimum version but no maximum version. I do it as below:

def LIB_MIN_VERSION = '2.16.0'

testCompile('some-library') {
  version {
    strictly [LIB_MIN_VERSION,)
  }
}

From the documentation on versioning, ) means an exclusive bound, and when an upper bound is missing, there is no upper bound.

When I run ./gradlew dependencies, I get this error:

> startup failed:
  build file '/home/shane/src/flink-svc/build.gradle': 119: expecting ']', found ')' @ line 119, column 33.
           strictly [LIB_MIN_VERSION,)
                                     ^

If I change to strictly [LIB_MIN_VERSION,] and rerun, I instead get this error:

> Could not get unknown property 'strictly' for  of type org.gradle.api.internal.artifacts.dependencies.DefaultMutableVersionConstraint.

Is it possible this range feature isn't available in my version of gradle? Or am I making a syntax error?

I tried @Slaw's suggestion to quote the range as strictly '[LIB_MIN_VERSION,)'. When I do, I don't get an error running ./gradlew dependencies, but in the output the resolution shows as failed:

some-library:{strictly [LIB_MIN_VERSION,)} FAILED

If I use strictly LIB_MIN_VERSION without a range (with is undesirable), then I don't get FAILED:

some-library:{strictly 2.16.0} -> 2.16.0

The dependency resolution also shows as FAILED if I try using Groovy string interpolation with strictly "[${LOG4J_LIB_VERSION},)":

some-library:{strictly [2.16.0,)} FAILED