recordio.pack and unpack of header inconsistency (outputting wrong result)

[pultarmi]

Description

mxnet.recordio.pack followed by mxnet.recordio.unpack is returning wrong result.

Input:
HEADER(flag=2, label=17672687.0, id=0, id2=0)

Expected output:
HEADER(flag=2, label=17672687.0, id=0, id2=0)

Actual output:
HEADER(flag=0, label=17672688.0, id=0, id2=0)

To Reproduce

import mxnet as mx

header = mx.recordio.IRHeader(flag=2, label=17672687.0, id=0, id2=0)
s = mx.recordio.pack(header, b'')
header_ = mx.recordio.unpack(s)[0]
print('original header ', header)
print('header packed and unpacked', header_)

What have you tried to solve it?

Tried different versions of Python (3.9.0, 3.8.3, 3.6.13) and of mxnet (mxnet==1.7.0.post1 and mxnet==1.5.0)

Environment

Python 3.9.0, mxnet==1.7.0.post1

[github-actions]

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