Maybe this will allow multiple lines going to GITHUB_OUTPUT

.github/workflows/isolated-release.yml

@@ -29,10 +29,10 @@ jobs:
           key_fingerprint=$(echo $key_fingerprint_and_email | awk '{print $1}')
           key_email=$(echo $key_fingerprint_and_email | awk '{print $2}')
           
-          {
-            "key_fingerprint=$key_fingerprint"
-            "key_email=$key_email"
-          } >> $GITHUB_OUTPUT
+          cat << EndOfFile >> $GITHUB_OUTPUT
+          key_fingerprint=$key_fingerprint
+          key_email=$key_email"
+          EndOfFile
 
   generate-version-update-commits:
     name: Generate Version Update Commits
@@ -49,10 +49,12 @@ jobs:
           git config user.email "[email protected]"
           git config user.name "Untrusted With Signing Privileges"
           sbt "release with-defaults"
+          echo $GITHUB_WORKSPACE
           cd `mktemp -d`
           git clone --bare $GITHUB_WORKSPACE repo-with-unsigned-version-update-commits.git
-          rm -Rf $GITHUB_WORKSPACE
-          mv repo-with-unsigned-version-update-commits.git $GITHUB_WORKSPACE
+          rm -Rf $GITHUB_WORKSPACE/*
+          mv repo-with-unsigned-version-update-commits.git $GITHUB_WORKSPACE/
+          ls -lR $GITHUB_WORKSPACE
       - uses: actions/cache/save@v3
         with:
           path: repo-with-unsigned-version-update-commits.git
@@ -75,6 +77,7 @@ jobs:
           fail-on-cache-miss: true
       - uses: actions/setup-java@v3
         with:
+          distribution: corretto
           java-version: 17
           gpg-private-key: ${{ secrets.AUTOMATED_MAVEN_RELEASE_PGP_SECRET }}
       - name: Create commit
@@ -97,10 +100,10 @@ jobs:
           
           release_commit_id=$(git rev-parse HEAD^)
           
-          {
-            "release_tag=$release_tag"
-            "release_commit_id=$release_commit_id"
-          } >> $GITHUB_OUTPUT
+          cat << EndOfFile >> $GITHUB_OUTPUT
+          release_tag=$release_tag
+          release_commit_id=$release_commit_id
+          EndOfFile
           
           git log --oneline -n3
           git push
@@ -172,10 +175,10 @@ jobs:
           fail-on-cache-miss: true
       - name: Create tiny sbt project to perform Sonatype upload
         run: |
-          cat <<EOT > build.sbt
+          cat << EndOfFile > build.sbt
           sonatypeBundleDirectory := new File("/tmp/funky")
           sonatypeProfileName := "com.gu"
-          EOT
+          EndOfFile
           
           mkdir project
           echo 'addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.9.21")' > project/plugins.sbt

build.sbt

@@ -62,12 +62,7 @@ lazy val `etag-caching-root` = (project in file("."))
       setReleaseVersion,
       commitReleaseVersion,
       tagRelease,
-      pushChanges,
-      // For non cross-build projects, use releaseStepCommand("publishSigned")
-      releaseStepCommandAndRemaining("+publishSigned"),
-      releaseStepCommand("sonatypeBundleRelease"),
       setNextVersion,
-      commitNextVersion,
-      pushChanges
+      commitNextVersion
     )
   )