@@ -5,7 +5,7 @@ RUN /setup/apt

 WORKDIR /root

 ARG version=master

-ENV version=$version

+ENV version=$DOCKER_TAG

 RUN /setup/checkout

@@ -4,4 +4,9 @@ set -eu -o pipefail

 git clone git://git.code.sf.net/p/sbcl/sbcl /sbcl-build

 cd /sbcl-build

+

+if [[ "$version" == "latest" ]]; then

+  version=master

+fi

+

 git checkout "${version}"