Temporarily fix bundler version mismatch.

See Automattic/a8c-ci-toolkit-buildkite-plugin#16

Author: AliSoftware

.buildkite/pipeline.yml

@@ -12,7 +12,10 @@ steps:
   #################
   - label: "🧪 Build and Test"
     key: "test"
-    command: "build_and_test_pod"
+    command: |
+      # See https://github.com/Automattic/bash-cache-buildkite-plugin/issues/16
+      gem install bundler:2.3.4
+      build_and_test_pod
     env: *common_env
     plugins: *common_plugins
 
@@ -21,7 +24,10 @@ steps:
   #################
   - label: "🔬 Validate Podspec"
     key: "validate"
-    command: "validate_podspec"
+    command: |
+      # See https://github.com/Automattic/bash-cache-buildkite-plugin/issues/16
+      gem install bundler:2.3.4
+      validate_podspec
     env: *common_env
     plugins: *common_plugins
 
@@ -30,7 +36,10 @@ steps:
   #################
   - label: "🧹 Lint"
     key: "lint"
-    command: "lint_pod"
+    command: |
+      # See https://github.com/Automattic/bash-cache-buildkite-plugin/issues/16
+      gem install bundler:2.3.4
+      lint_pod
     env: *common_env
     plugins: *common_plugins
 

.buildkite/publish-pod.sh

@@ -5,6 +5,9 @@ SPECS_REPO="[email protected]:wordpress-mobile/cocoapods-specs.git"
 SLACK_WEBHOOK=$PODS_SLACK_WEBHOOK
 
 echo "--- :rubygems: Setting up Gems"
+# See https://github.com/Automattic/bash-cache-buildkite-plugin/issues/16
+gem install bundler:2.3.4
+
 install_gems
 
 echo "--- :cocoapods: Publishing Pod to CocoaPods CDN"