Add a snapshot of flutter/engine/src/build to our sdk

build/env_dump.py

Index: build/env_dump.py
diff --git a/build/env_dump.py b/build/env_dump.py
new file mode 100755
index 0000000000000000000000000000000000000000..21edfe633c718ed8f96bd091731fa305da654821
--- /dev/null
+++ b/build/env_dump.py
@@ -0,0 +1,56 @@
+#!/usr/bin/python
+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This script can either source a file and dump the enironment changes done by
+# it, or just simply dump the current environment as JSON into a file.
+
+import json
+import optparse
+import os
+import pipes
+import subprocess
+import sys
+
+
+def main():
+  parser = optparse.OptionParser()
+  parser.add_option('-f', '--output-json',
+                    help='File to dump the environment as JSON into.')
+  parser.add_option(
+      '-d', '--dump-mode', action='store_true',
+      help='Dump the environment to sys.stdout and exit immediately.')
+
+  parser.disable_interspersed_args()
+  options, args = parser.parse_args()
+  if options.dump_mode:
+    if args or options.output_json:
+      parser.error('Cannot specify args or --output-json with --dump-mode.')
+    json.dump(dict(os.environ), sys.stdout)
+  else:
+    if not options.output_json:
+      parser.error('Requires --output-json option.')
+
+    envsetup_cmd = ' '.join(map(pipes.quote, args))
+    full_cmd = [
+        'bash', '-c',
+        '. %s > /dev/null; %s -d' % (envsetup_cmd, os.path.abspath(__file__))
+    ]
+    try:
+      output = subprocess.check_output(full_cmd)
+    except Exception as e:
+      sys.exit('Error running %s and dumping environment.' % envsetup_cmd)
+
+    env_diff = {}
+    new_env = json.loads(output)
+    for k, val in new_env.items():
+      if k == '_' or (k in os.environ and os.environ[k] == val):
+        continue
+      env_diff[k] = val
+    with open(options.output_json, 'w') as f:
+      json.dump(env_diff, f)
+
+
+if __name__ == '__main__':
+  sys.exit(main())