Automate publishLocal step for slow/test

sbt can be fun sometimes

.travis.yml

@@ -18,7 +18,10 @@ jobs:
         - sbt scalafixCheck docs/docusaurusCreateSite
     - env: TEST="sbt slow/test"
       script:
-        - sbt sbt-metals/publishLocal slow/test
+        - sbt slow/test
+    - env: TEST="sbt +cross/test"
+      script:
+        - sbt +cross/test
     - stage: release
       script: sbt ci-release docs/docusaurusPublishGhpages
 

build.sbt

@@ -323,10 +323,36 @@ lazy val unit = project
   )
   .dependsOn(mtest, metals, pc)
   .enablePlugins(BuildInfoPlugin)
+
+val cross211publishLocal = Def.task[Unit] {
+  // Runs `publishLocal` for mtags/pc with 2.11 scalaVersion.
+  val newState = Project
+    .extract(state.value)
+    .appendWithSession(
+      List(
+        scalaVersion.in(mtags) := V.scala211,
+        scalaVersion.in(pc) := V.scala211
+      ),
+      state.value
+    )
+  Project
+    .extract(newState)
+    .runTask(publishLocal.in(mtags), newState)
+  Project
+    .extract(newState)
+    .runTask(publishLocal.in(pc), newState)
+}
 lazy val slow = project
   .in(file("tests/slow"))
   .settings(
-    testSettings
+    testSettings,
+    test.in(Test) := test
+      .in(Test)
+      .dependsOn(
+        publishLocal.in(`sbt-metals`),
+        cross211publishLocal
+      )
+      .value
   )
   .dependsOn(unit)