message: Use "echo + append" rather than "sed -i" in flatbuffers bzl.
diff: @@ -353,14 +353,14 @@ def _concat_flatbuffer_py_srcs_impl(ctx):
  # Merge all generated python files. The files are concatenated and the
  # import statements are removed. Finally we import the flatbuffer runtime
  # library.
  - command = "for f in $(find %s -name '*.py'); do cat $f | sed '/import flatbuffers/d' >> %s; done; "
  - command += "sed -i '1s/^/import flatbuffers\\'$'\\n/' %s"
  + command = "echo 'import flatbuffers\n' > %s; "
  + command += "for f in $(find %s -name '*.py'); do cat $f | sed '/import flatbuffers/d' >> %s; done "
  ctx.actions.run_shell(
  inputs = ctx.attr.deps[0].files,
  outputs = [ctx.outputs.out],
  command = command % (
  - ctx.attr.deps[0].files.to_list()[0].path,
  ctx.outputs.out.path,
  + ctx.attr.deps[0].files.to_list()[0].path,
  ctx.outputs.out.path,
  ),
  )
  