From 642a4ff24097226d56040909b27555ad4fa1b1ef Mon Sep 17 00:00:00 2001
From: Andrzej Janczak <andrzej.janczak@codacy.com>
Date: Thu, 20 Aug 2026 10:02:24 +0200
Subject: [PATCH 1/2] feature: skip the openjdk install when the JVM is already
 on the image

Problem: every sbt job spends ~44 MB and tens of seconds on `apt install
openjdk-N-jre`. The machine images already carry JDK 8, 17 and 21, so apt was
only upgrading an installed package (17.0.13 -> 17.0.15 on ubuntu-2004).
Fix: install only when the JVM directory is absent, and always switch the
default. JDK 11 is the only version genuinely missing from the images.
---
 src/jobs/sbt.yml | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/jobs/sbt.yml b/src/jobs/sbt.yml
index 9185df59..402cbfbc 100644
--- a/src/jobs/sbt.yml
+++ b/src/jobs/sbt.yml
@@ -89,9 +89,15 @@ steps:
             environment:
               OJDK_VERSION: << parameters.openjdk_version >>
             command: |
-              sudo apt update
-              sudo apt install openjdk-${OJDK_VERSION}-jre
-              sudo update-alternatives --set java /usr/lib/jvm/java-${OJDK_VERSION}-openjdk-amd64/bin/java
+              JVM_DIR="/usr/lib/jvm/java-${OJDK_VERSION}-openjdk-amd64"
+              # machine images already carry 8, 17 and 21; apt would only upgrade them
+              if [ -d "$JVM_DIR" ]; then
+                echo "openjdk-${OJDK_VERSION} already present at ${JVM_DIR}, skipping install"
+              else
+                sudo apt update
+                sudo apt install -y "openjdk-${OJDK_VERSION}-jre"
+              fi
+              sudo update-alternatives --set java "${JVM_DIR}/bin/java"
   - when:
       condition: << parameters.install_sbt_version >>
       steps:

From 08098babb1fe0df3a887c53693497d203c78418a Mon Sep 17 00:00:00 2001
From: Andrzej Janczak <andrzej.janczak@codacy.com>
Date: Thu, 20 Aug 2026 10:47:15 +0200
Subject: [PATCH 2/2] fix: guard on the registered alternative, not the
 directory

A directory can exist without update-alternatives knowing about it, and the
--set below would then fail. Testing the alternative tests the actual
precondition.
---
 src/jobs/sbt.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/jobs/sbt.yml b/src/jobs/sbt.yml
index 402cbfbc..9b905f42 100644
--- a/src/jobs/sbt.yml
+++ b/src/jobs/sbt.yml
@@ -90,9 +90,9 @@ steps:
               OJDK_VERSION: << parameters.openjdk_version >>
             command: |
               JVM_DIR="/usr/lib/jvm/java-${OJDK_VERSION}-openjdk-amd64"
-              # machine images already carry 8, 17 and 21; apt would only upgrade them
-              if [ -d "$JVM_DIR" ]; then
-                echo "openjdk-${OJDK_VERSION} already present at ${JVM_DIR}, skipping install"
+              # skip only when the exact alternative the --set below needs is already registered
+              if update-alternatives --list java 2>/dev/null | grep -qx "${JVM_DIR}/bin/java"; then
+                echo "openjdk-${OJDK_VERSION} already registered at ${JVM_DIR}, skipping install"
               else
                 sudo apt update
                 sudo apt install -y "openjdk-${OJDK_VERSION}-jre"