Test compilation of all arches

* Add compile_all step to Makefile
  * Add this to travis
  * Add -compile-only flag to cross-compile.go to save time making the zips

.travis.yml

@@ -15,6 +15,7 @@ install:
 script:
 - make check
 - make quicktest
+- make compile_all
 env:
   global:
     - GOTAGS=cmount

Makefile

@@ -123,6 +123,13 @@ upload_beta:
 	rclone --config bin/travis.rclone.conf -v copy --include '*beta-latest*' build/ memstore:beta-rclone-org
 	@echo Beta release ready at $(BETA_URL)
 
+compile_all:
+ifdef GO_LATEST
+	go run bin/cross-compile.go -parallel 8 -compile-only $(BUILDTAGS) $(TAG)β
+else
+	@echo Skipping compile all as not on Go stable
+endif
+
 travis_beta:
 	git log $(LAST_TAG).. > /tmp/git-log.txt
 	go run bin/cross-compile.go -release beta-latest -git-log /tmp/git-log.txt -exclude "^windows/" -parallel 8 $(BUILDTAGS) $(TAG)β

bin/cross-compile.go

@@ -28,6 +28,7 @@ var (
 	cgo         = flag.Bool("cgo", false, "Use cgo for the build")
 	noClean     = flag.Bool("no-clean", false, "Don't clean the build directory before running.")
 	tags        = flag.String("tags", "", "Space separated list of build tags")
+	compileOnly = flag.Bool("compile-only", false, "Just build the binary, not the zip.")
 )
 
 // GOOS/GOARCH pairs we build for
@@ -117,6 +118,7 @@ func compileArch(version, goos, goarch, dir string) {
 		env = append(env, flags...)
 	}
 	runEnv(args, env)
+	if !*compileOnly {
 		// Now build the zip
 		run("cp", "-a", "../MANUAL.txt", filepath.Join(dir, "README.txt"))
 		run("cp", "-a", "../MANUAL.html", filepath.Join(dir, "README.html"))
@@ -131,6 +133,7 @@ func compileArch(version, goos, goarch, dir string) {
 			run("ln", zip, copyAsZip)
 		}
 		run("rm", "-rf", dir)
+	}
 	log.Printf("Done compiling %s/%s", goos, goarch)
 }