Speedup builds with bazel remote disk caching (#62)

This PR adds remote disk caching to all make / CI builds

.travis.yml

@@ -3,5 +3,10 @@ os:
   - osx
 before_install:
   - sudo gem install cocoapods
+cache:
+  directories:
+    - $HOME/.bazelenv
+    - $HOME/Library/Caches/Bazel
+    - $HOME/.bazel_pod_store
 osx_image: xcode10
 script: make ci

Examples/Example.Makefile

@@ -8,15 +8,20 @@ BAZEL_WRAPPER=$(RULES_PODS_DIR)/tools/bazelwrapper
 # Currently `bazelwrapper` relies on pwd, which causes issues here
 BAZEL=~/.bazelenv/versions/0.18.0/bin/bazel
 
+# Override the repository to point at the source. It does a source build of the
+# current code.
+BAZEL_OPTS=--override_repository=rules_pods=$(RULES_PODS_DIR) \
+		--disk_cache=$(HOME)/Library/Caches/Bazel
+
 all: fetch build
 
 # Build everything in this workspace
 .PHONY: build
 build: info 
-	$(BAZEL) build :* --override_repository=rules_pods=$(RULES_PODS_DIR)
+	$(BAZEL) build :* $(BAZEL_OPTS)
 
 test: info 
-	$(BAZEL) test :* --override_repository=rules_pods=$(RULES_PODS_DIR)
+	$(BAZEL) test :* $(BAZEL_OPTS)
 
 # Fetch vendored pods if there's a Pods.WORKSPACE. In normal operation it isn't
 # expected to run `update_pods` along with a build.

Makefile

@@ -80,6 +80,8 @@ ci: clean
 
 release:
 	@tools/bazelwrapper build \
+		--disk_cache=$(HOME)/Library/Caches/Bazel \
+		--spawn_strategy=standalone \
 		-c opt \
 		--swiftcopt=-whole-module-optimization :RepoTools :Compiler
 	@ditto bazel-bin/RepoTools bin/RepoTools