The "groovy-2.4" version of Spock is fully compatible with 2.5.x and 2.6.x.
It is also compatible at the moment with 3.0.x but has logic within to reject that version.
Snapshot versions of Spock are at the moment more lenient wrt that version checking so you can use any snapshot version with Groovy 3.0.x.

Cheers, Paul.

On Fri, Mar 23, 2018 at 10:04 PM, Russel Winder <russel@winder.org.uk> wrote:
Hi,

With all the versions of Groovy currently released, there is a problem
that anyone using  Spock seems to be stuck on Groovy 2.4.x because the
latest version of Spock is 1.1-groovy-2.4 and so there is no reliable
Spock for Groovy 2.5.x, 2.6.x or 3.0.x.

--
Russel.
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