dev/devcam: don't invoke make.go four times for four targets

Just once is fine.

Change-Id: I74b34f34ee5a193dcf7ac7d28acc858fd6263a68

dev/devcam/devcam.go

@@ -233,26 +233,35 @@ func checkModtime() error {
 	return nil
 }
 
-// Build builds the camlistore command at the given path from the source tree root.
-func build(path string) error {
+// build builds the named perkeep targets.
+// Each target may have its "perkeep.org" prefix removed.
+func build(targets ...string) error {
 	if v, _ := strconv.ParseBool(os.Getenv("CAMLI_FAST_DEV")); v {
 		// Demo mode. See dev/demo.sh.
 		return nil
 	}
-	target := pathpkg.Join("perkeep.org", filepath.ToSlash(path))
+	var fullTargets []string
+	for _, t := range targets {
+		t = filepath.ToSlash(t)
+		if !strings.HasPrefix(t, "perkeep.org") {
+			t = pathpkg.Join("perkeep.org", t)
+		}
+		fullTargets = append(fullTargets, t)
+	}
+	targetsComma := strings.Join(fullTargets, ",")
 	args := []string{
 		"run", "make.go",
 		"--quiet",
 		"--race=" + strconv.FormatBool(*race),
 		"--embed_static=false",
 		"--sqlite=" + strconv.FormatBool(withSqlite),
-		"--targets=" + target,
+		"--targets=" + targetsComma,
 	}
 	cmd := exec.Command("go", args...)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	if err := cmd.Run(); err != nil {
-		return fmt.Errorf("Error building %v: %v", target, err)
+		return fmt.Errorf("error building %v: %v", targetsComma, err)
 	}
 	return nil
 }

dev/devcam/server.go

@@ -100,7 +100,7 @@ func init() {
 		flags.BoolVar(&cmd.debug, "debug", false, "Enable http debugging.")
 		flags.BoolVar(&cmd.sha1, "sha1", false, "Use sha1 instead of sha224.")
 		flags.BoolVar(&cmd.publish, "publish", true, "Enable publisher app(s)")
-		flags.BoolVar(&cmd.scancab, "scancab", true, "Enable scancab app(s)")
+		flags.BoolVar(&cmd.scancab, "scancab", false, "Enable scancab app(s)")
 		flags.BoolVar(&cmd.hello, "hello", false, "Enable hello (demo) app")
 		flags.BoolVar(&cmd.mini, "mini", false, "Enable minimal mode, where all optional features are disabled. (Currently just publishing)")
 
@@ -511,17 +511,15 @@ func (c *serverCmd) RunCommand(args []string) error {
 			filepath.Join("cmd", "pk"),
 		}
 		if c.hello {
-			targets = append(targets, filepath.Join("app", "hello"))
+			targets = append(targets, "app/hello")
 		}
 		if c.publish {
-			targets = append(targets, filepath.Join("app", "publisher"))
+			targets = append(targets, "app/publisher")
 		}
-		targets = append(targets, filepath.Join("app", "scanningcabinet"))
-		for _, name := range targets {
-			err := build(name)
-			if err != nil {
-				return fmt.Errorf("Could not build %v: %v", name, err)
-			}
+		targets = append(targets, "app/scanningcabinet")
+		err := build(targets...)
+		if err != nil {
+			return err
 		}
 	}
 	if err := c.setRoot(); err != nil {