This is a very lazy question

you don't say where in China you are.
it is a very big country.
are you in a big city such as Shanghai or Beijing, or somewhere smaller and less international?

have you tried using a search engine or asking a local?
or are you just so lazy you have done nothing but post here asking asking strangers?

if there is not place in your city that sells rye bread, this is certainly not something i would order online as you are asking to be scammed with potentially toxic food.

to be honest, I don't think you are a genuine poster - especially if you don't respond 

here is a hint for free.

If i want to locate something and am asking on an internet forum i would include the following in the question:

"I am located in (city) and am looking for (item)
I have tried this (search engine or anything else I have already done) and asked local friends/colleagues.
If you have lived in (city name) do you know anywhere, or have any suggestions as to how else I can find (item)
Thanks"

You're welcome

Fuk-ang, Xinjiang, but only at the small Uyghur's bakery shacks, if they still exist. 

Rye and pure corn bread, which are both baked as 150g or so brioches and focaccias. Year 2012/13.

You might also try in Kaifeng or in Henan overall, anywhere with the larger Uyghur populus.

I've lived and worked in both places. Nowhere else in China they sell rye bread.

I'd say, selling of any darker color bread in China wouldn't fly 'cause ... of the darker bread color.

If you don't understand the color matter in China, find out why all Chinese walk with an open umbrellas at sunny weather ... or why tanned Chinese farmers are treated as a second grade citizens ...