temp repro

BUILD

@@ -1,6 +1,6 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 load("@bazel_tools//tools/build_defs/pkg:pkg.bzl", "pkg_tar")
-load("//src/undocker:rules.bzl", "rootfs")
+load("//src/undocker:rules.bzl", "rootfs", "temp")
 load(
     "@io_bazel_rules_docker//container:container.bzl",
     "container_bundle",
@@ -34,3 +34,15 @@ rootfs(
     #src = "@alpine//image:image",
     src = ":alpine-container-plus",
 )
+
+filegroup(
+    name = "maingo",
+    srcs = ["main.go"],
+    visibility = ["//visibility:public"],
+)
+
+temp(
+    name = "temp",
+    data = ":maingo",
+    out = "maingo.txt",
+)