support specifying a name on cmdline building

lilac

@@ -577,7 +577,11 @@ def main_may_raise(
 
   if pkgs_from_args:
     for p in pkgs_from_args:
-      build_reasons[p].append(BuildReason.Cmdline())
+      if ':' in p:
+        p, runner = p.split(':', 1)
+      else:
+        runner = None
+      build_reasons[p].append(BuildReason.Cmdline(runner))
 
   for p in need_rebuild_pkgrel:
     build_reasons[p].append(BuildReason.UpdatedPkgrel())

lilac2/nomypy.py

@@ -1,6 +1,6 @@
 # type: ignore
 
-from typing import Union
+from typing import Union, Optional
 
 from .typing import OnBuildEntry
 
@@ -96,7 +96,15 @@ class FailedByDeps(BuildReason):
   def __init__(self, deps: tuple[str]) -> None:
     self.deps = deps
 
-class Cmdline(BuildReason): pass
+class Cmdline(BuildReason):
+  def __init__(self, runner: Optional[str]) -> None:
+    self.runner = runner
+
+  def _extra_info(self) -> str:
+    if self.runner:
+      return repr(self.runner)
+    else:
+      return ''
 
 class OnBuild(BuildReason):
   def __init__(self, update_on_build: list[OnBuildEntry]) -> None: