Don't use large UIDs in tar files on Linux.

lib/src/io.dart

Index: lib/src/io.dart
diff --git a/lib/src/io.dart b/lib/src/io.dart
index 69248cdb8a2f30d1dcf8959a11d3e66e07f8bd77..9ea932de0f031f14c113fa0edf1d55e2f977a25b 100644
--- a/lib/src/io.dart
+++ b/lib/src/io.dart
@@ -1012,7 +1012,7 @@ ByteStream createTarGz(List contents, {String baseDir}) {
       return path.relative(entry, from: baseDir);
     }).toList();
 
-    if (Platform.operatingSystem != "windows") {
+    if (!Platform.isWindows) {
       var args = [
         // ustar is the most recent tar format that's compatible across all
         // OSes.
@@ -1025,6 +1025,12 @@ ByteStream createTarGz(List contents, {String baseDir}) {
         "/dev/stdin"
       ];
 
+      // The ustar format doesn't support large UIDs, which can happen if
+      // someone's using Active Directory on Linux. We don't care about
+      // preserving ownership anyway, so we just set them to 0. Note that BSD
+      // tar doesn't support the `--owner` or `--group` arguments.
+      if (Platform.isLinux) args.addAll(["--owner=0", "--group=0"]);
+
       var process = await startProcess("tar", args);
       process.stdin.add(UTF8.encode(contents.join("\n")));
       process.stdin.close();