🔥 Copy fresh Gemfile for Ruby 2.5 each time devcontainer is run

Author: pboling

.devcontainer/2.5/bundle-config/install.sh

@@ -2,5 +2,8 @@
 RUBYGEMS_VERSION=3.3.27
 gem install rubygems-update -v ${RUBYGEMS_VERSION} > /dev/null 2>&1 &&
 update_rubygems > /dev/null 2>&1
+# Depends on making a copy of the Gemfile, so we don't conflict with the Gemfile.lock
+#   that is probably relegated to newer Ruby.
+# We need to set the ENV variable here, but must wait to copy the Gemfile until the postCreateCommand hook.
 # Ensure we use the right Gemfile
 echo 'export BUNDLE_GEMFILE=Gemfile-ruby2_5.gemfile' >> ~/.bashrc

.devcontainer/2.5/devcontainer.json

@@ -3,7 +3,7 @@
 {
   "name": "Ruby 2.5 on Debian",
   "image": "ruby:2.5-buster",
-  "postCreateCommand": "bundle install",
+  "postCreateCommand": "cp Gemfile Gemfile-ruby2_5.gemfile && bundle install",
 
   // Features to add to the dev container. More info: https://containers.dev/features.
   // Features run during the image build, and thus before the lifecycle hooks in this file, e.g., postCreateCommand

.gitignore

@@ -7,3 +7,5 @@
 /spec/reports/
 /tmp/
 Gemfile.lock
+*.gemfile
+*.gemfile.lock