diff --git a/corral/cmd/_test.pony b/corral/cmd/_test.pony
new file mode 100644
index 00000000..8ebb2220
--- /dev/null
+++ b/corral/cmd/_test.pony
@@ -0,0 +1,11 @@
+use "ponytest"
+
+actor Main is TestList
+  new create(env: Env) =>
+    PonyTest(env, this)
+
+  new make() =>
+    None
+
+  fun tag tests(test: PonyTest) =>
+   _TestCmdUpdate.make().tests(test)
diff --git a/corral/cmd/_test_cmd_update.pony b/corral/cmd/_test_cmd_update.pony
new file mode 100644
index 00000000..e2741a13
--- /dev/null
+++ b/corral/cmd/_test_cmd_update.pony
@@ -0,0 +1,146 @@
+use "files"
+use "ponytest"
+use "../bundle"
+use "../util"
+use "../vcs"
+
+actor _TestCmdUpdate is TestList
+  new make() =>
+    None
+
+  fun tag tests(test: PonyTest) =>
+    test(_TestEmptyDeps)
+
+class iso _TestEmptyDeps is UnitTest
+  fun name(): String =>
+    "cmd/update/" + __loc.type_name()
+
+  fun apply(h: TestHelper) ? =>
+    """
+    Verify that when using an corral.json for with empty deps, that there
+    are never any sync, tag query, or checkout operations executed.
+    """
+    let auth = h.env.root as AmbientAuth
+    let log = Log(LvlNone, h.env.err, SimpleLogFormatter)
+    let fp: FilePath = _TestData.file_path_from(h, "empty-deps")?
+    let repo_cache = _TestRepoCache(auth)?
+    let ctx = Context(h.env, log, log, false, repo_cache)
+    let project = Project(auth, log, fp)
+    let bundle = Bundle.load(fp, log)?
+    let recorder = _OpsRecorder(h, 0, 0, 0)
+    let vcs_builder: VCSBuilder = _TestCmdUpdateVCSBuilder(recorder)
+
+    let updater = _Updater(ctx, project, consume bundle, vcs_builder, recorder)
+
+    // when updater is finished, it will send a `cmd_completed` message to
+    // _OpsRecorder which will trigger pass/fail
+    h.long_test(2_000_000_000)
+
+
+actor _OpsRecorder is CmdResultReceiver
+  let _h: TestHelper
+
+  let _expected_sync: U64
+  let _expected_tag_query: U64
+  let _expected_checkout: U64
+
+  var _sync: U64 = 0
+  var _tag_query: U64 = 0
+  var _checkout: U64 = 0
+
+  new create(h: TestHelper, s: U64, tq: U64, c: U64) =>
+    _h = h
+    _expected_sync = s
+    _expected_tag_query = tq
+    _expected_checkout = c
+
+  be sync() =>
+    _sync = _sync + 1
+
+  be tag_query() =>
+    _tag_query = _tag_query + 1
+
+  be checkout() =>
+    _checkout = _checkout + 1
+
+  be cmd_completed() =>
+    _h.assert_eq[U64](_expected_sync, _sync)
+    _h.assert_eq[U64](_expected_tag_query, _tag_query)
+    _h.assert_eq[U64](_expected_checkout, _checkout)
+
+    _h.complete(true)
+
+
+class val _TestCmdUpdateVCSBuilder is VCSBuilder
+  let _recorder: _OpsRecorder
+
+  new val create(recorder: _OpsRecorder) =>
+    _recorder = recorder
+
+  fun val apply(kind: String): VCS =>
+    _RecordedVCS(_recorder)
+
+
+class val _RecordedVCS is VCS
+  let _recorder: _OpsRecorder
+
+  new val create(recorder: _OpsRecorder) =>
+    _recorder = recorder
+
+  fun val sync_op(next: RepoOperation): RepoOperation =>
+    _RecordedSync(_recorder, next)
+
+  fun val tag_query_op(receiver: TagListReceiver): RepoOperation =>
+    _RecordedTagQuery(_recorder, receiver)
+
+  fun val checkout_op(rev: String, next: RepoOperation): RepoOperation =>
+    _RecordedCheckout(_recorder, next)
+
+
+class val _RecordedSync is RepoOperation
+  let _recorder: _OpsRecorder
+  let _next: RepoOperation
+
+  new val create(recorder: _OpsRecorder, next: RepoOperation) =>
+    _recorder = recorder
+    _next = next
+
+  fun val apply(repo: Repo) =>
+    _recorder.sync()
+    _next(repo)
+
+
+class val _RecordedTagQuery is RepoOperation
+  let _recorder: _OpsRecorder
+  let _next: TagListReceiver
+
+  new val create(recorder: _OpsRecorder, next: TagListReceiver) =>
+    _recorder = recorder
+    _next = next
+
+  fun val apply(repo: Repo) =>
+    let tags: Array[String] iso = recover Array[String] end
+    _recorder.tag_query()
+    _next(repo, consume tags)
+
+
+class val _RecordedCheckout is RepoOperation
+  let _recorder: _OpsRecorder
+  let _next: RepoOperation
+
+  new val create(recorder: _OpsRecorder, next: RepoOperation) =>
+    _recorder = recorder
+    _next = next
+
+  fun val apply(repo: Repo) =>
+    _recorder.checkout()
+    _next(repo)
+
+primitive _TestData
+  fun file_path_from(h: TestHelper, subdir: String = ""): FilePath ? =>
+    let auth = h.env.root as AmbientAuth
+    FilePath(auth, "corral/test/testdata")?.join(subdir)?
+
+primitive _TestRepoCache
+  fun apply(auth: AmbientAuth): FilePath ? =>
+    FilePath(auth,"_test_cmd_update_repo_cache")?
diff --git a/corral/cmd/cmd_add.pony b/corral/cmd/cmd_add.pony
index 56786a0f..c78d4dcc 100644
--- a/corral/cmd/cmd_add.pony
+++ b/corral/cmd/cmd_add.pony
@@ -14,7 +14,11 @@ class CmdAdd is CmdType
     version = cmd.option("version").string()
     revision = cmd.option("revision").string()
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info(
       "add: adding: " + locator + " " + version + " " + revision)
 
diff --git a/corral/cmd/cmd_clean.pony b/corral/cmd/cmd_clean.pony
index 93a945e6..a3f6d008 100644
--- a/corral/cmd/cmd_clean.pony
+++ b/corral/cmd/cmd_clean.pony
@@ -19,7 +19,11 @@ class CmdClean is CmdType
     // clean_corral
     true
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info(
       "clean: corral:" + clean_corral.string() +
       " repos:" + clean_repos.string())
diff --git a/corral/cmd/cmd_fetch.pony b/corral/cmd/cmd_fetch.pony
index 3097729c..4c39d531 100644
--- a/corral/cmd/cmd_fetch.pony
+++ b/corral/cmd/cmd_fetch.pony
@@ -9,7 +9,11 @@ class CmdFetch is CmdType
 
   new create(cmd: Command) => None
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("fetch: fetching from " + project.dir.path)
 
     match project.load_bundle()
diff --git a/corral/cmd/cmd_info.pony b/corral/cmd/cmd_info.pony
index 7af41279..a2644393 100644
--- a/corral/cmd/cmd_info.pony
+++ b/corral/cmd/cmd_info.pony
@@ -8,7 +8,11 @@ class CmdInfo is CmdType
 
   new create(cmd: Command) => None
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("info: from " + project.dir.path)
 
     match project.load_bundle()
diff --git a/corral/cmd/cmd_init.pony b/corral/cmd/cmd_init.pony
index 1863118c..f5ccb2c5 100644
--- a/corral/cmd/cmd_init.pony
+++ b/corral/cmd/cmd_init.pony
@@ -11,7 +11,11 @@ class CmdInit is CmdType
   fun requires_bundle(): Bool => false
   fun requires_no_bundle(): Bool => true
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("init: in " + project.dir.path)
 
     // TODO: try to read first to convert/update existing file(s)
diff --git a/corral/cmd/cmd_list.pony b/corral/cmd/cmd_list.pony
index 82eaae10..268ba24a 100644
--- a/corral/cmd/cmd_list.pony
+++ b/corral/cmd/cmd_list.pony
@@ -8,7 +8,11 @@ class CmdList is CmdType
 
   new create(cmd: Command) => None
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("list: from " + project.dir.path)
 
     match project.load_bundle()
diff --git a/corral/cmd/cmd_remove.pony b/corral/cmd/cmd_remove.pony
index e4a35ffe..0518144d 100644
--- a/corral/cmd/cmd_remove.pony
+++ b/corral/cmd/cmd_remove.pony
@@ -10,7 +10,11 @@ class CmdRemove is CmdType
   new create(cmd: Command) =>
     locator = cmd.arg("locator").string()
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("remove: removing: " + locator)
 
     match project.load_bundle()
diff --git a/corral/cmd/cmd_run.pony b/corral/cmd/cmd_run.pony
index cfc820d1..367a4bfa 100644
--- a/corral/cmd/cmd_run.pony
+++ b/corral/cmd/cmd_run.pony
@@ -14,7 +14,11 @@ class CmdRun is CmdType
 
   fun requires_bundle(): Bool => false
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("run: " + " ".join(args.values()))
 
     // Build a : separated path from bundle roots.
diff --git a/corral/cmd/cmd_type.pony b/corral/cmd/cmd_type.pony
index ade39110..58046323 100644
--- a/corral/cmd/cmd_type.pony
+++ b/corral/cmd/cmd_type.pony
@@ -5,4 +5,7 @@ trait CmdType
   fun requires_bundle(): Bool => true
   fun requires_no_bundle(): Bool => false
 
-  fun ref apply(ctx: Context, project: Project, vcs_builder: VCSBuilder)
+  fun ref apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    results_receiver: CmdResultReceiver)
diff --git a/corral/cmd/cmd_update.pony b/corral/cmd/cmd_update.pony
index b7cba397..e9d862bf 100644
--- a/corral/cmd/cmd_update.pony
+++ b/corral/cmd/cmd_update.pony
@@ -6,14 +6,18 @@ use "../util"
 use "../vcs"
 
 class CmdUpdate is CmdType
+  new create(cmd: Command) =>
+    None
 
-  new create(cmd: Command) => None
-
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    results_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("update: updating from " + project.dir.path)
     match project.load_bundle()
     | let bundle: Bundle iso =>
-      _Updater(ctx, project, consume bundle, vcs_builder)
+      _Updater(ctx, project, consume bundle, vcs_builder, results_receiver)
     | let err: Error =>
       ctx.uout.err(err.message)
       ctx.env.exitcode(1)
@@ -29,16 +33,19 @@ actor _Updater
   let dep_tags: Map[Locator, Array[String] val] ref = dep_tags.create()
 
   let _vcs_builder: VCSBuilder
+  let _results_receiver: CmdResultReceiver
 
   new create(ctx': Context,
     project': Project,
     base_bundle': Bundle iso,
-    vcs_builder: VCSBuilder)
+    vcs_builder: VCSBuilder,
+    results_receiver: CmdResultReceiver)
   =>
     ctx = ctx'
     project = project'
     base_bundle = consume base_bundle'
     _vcs_builder = vcs_builder
+    _results_receiver = results_receiver
     ctx.log.info("Updating direct deps of project bundle: " + base_bundle.name())
     load_bundle_deps(base_bundle)
 
@@ -67,6 +74,9 @@ actor _Updater
         // It won't get a lock. How should we handle/report the error?
       end
     end
+    if deps_to_load.size() == 0 then
+      _results_receiver.cmd_completed()
+    end
 
   fun load_dep(dep: Dep) ? =>
     let vcs = _vcs_builder(dep.vcs())?
@@ -140,6 +150,7 @@ actor _Updater
         else
           ctx.uout.err("Error saving project bundle")
         end
+        _results_receiver.cmd_completed()
         // All done, should quiesce now...
         ctx.log.fine("try_complete all done.")
       end
diff --git a/corral/cmd/cmd_version.pony b/corral/cmd/cmd_version.pony
index d74a86a5..8c61dc4d 100644
--- a/corral/cmd/cmd_version.pony
+++ b/corral/cmd/cmd_version.pony
@@ -9,5 +9,9 @@ class CmdVersion is CmdType
 
   fun requires_bundle(): Bool => false
 
-  fun apply(ctx: Context, project: Project, vcs_builder: VCSBuilder) =>
+  fun apply(ctx: Context,
+    project: Project,
+    vcs_builder: VCSBuilder,
+    result_receiver: CmdResultReceiver)
+  =>
     ctx.uout.info("version: " + Version())
diff --git a/corral/cmd/executor.pony b/corral/cmd/executor.pony
index 5ae4e931..7c58ff39 100644
--- a/corral/cmd/executor.pony
+++ b/corral/cmd/executor.pony
@@ -103,5 +103,5 @@ primitive Executor
 
     let context = Context(env, log, uout, nothing, repo_cache)
     let project = Project(auth, log, bundle_dir)
-    let vcs_builder = VCSBuilder(env)
-    command(context, project, vcs_builder)
+    let vcs_builder = CorralVCSBuilder(env)
+    command(context, project, vcs_builder, NoOpResultReceiver)
diff --git a/corral/cmd/result_receiver.pony b/corral/cmd/result_receiver.pony
new file mode 100644
index 00000000..291e8025
--- /dev/null
+++ b/corral/cmd/result_receiver.pony
@@ -0,0 +1,6 @@
+interface tag CmdResultReceiver
+  be cmd_completed()
+
+primitive NoOpResultReceiver
+  fun tag cmd_completed() =>
+    None
diff --git a/corral/test/_test.pony b/corral/test/_test.pony
index c1988ee1..9fdcf841 100644
--- a/corral/test/_test.pony
+++ b/corral/test/_test.pony
@@ -1,6 +1,7 @@
 use "ponytest"
 use "files"
 use integration = "integration"
+use cmd = "../cmd"
 
 actor Main is TestList
   new create(env: Env) =>
@@ -23,3 +24,5 @@ actor Main is TestList
     test(integration.TestRun)
     test(integration.TestRunWithoutBundle)
     test(integration.TestClean)
+
+    cmd.Main.make().tests(test)
diff --git a/corral/vcs/vcs_builder.pony b/corral/vcs/vcs_builder.pony
index 091af69e..1a8563f2 100644
--- a/corral/vcs/vcs_builder.pony
+++ b/corral/vcs/vcs_builder.pony
@@ -1,4 +1,7 @@
-class val VCSBuilder
+interface val VCSBuilder
+  fun val apply(kind: String): VCS ?
+
+class val CorralVCSBuilder
   let _env: Env
 
   new val create(env: Env) =>