Spent some hours - experimenting...

So - short story - it works. There remains a big chance for failure though as the current tag ignores differences in TL level, build_date, etc.. Also, a source for failure, is no recognition for 32-bit or 64-bit.

However, focusing on the good news - the wheels install - without a compiler being called.

Looking Forward!!
AIX has a long history of letting binaries from the past be reused: See: https://www.ibm.com/support/knowledgecenter/ssw_aix_72/install/binary_compatability.html

++++++ The gritty details, for the curious/interested

After having used devpi (client) to upload to a test devpi-server I pointed my pip at the devpi-server to download the packages.

Note: using default pipy "source" I would get two .gz files.

The initial upload is from an AIX 6.1 server, the download here is to an AIX 7.1 server.

(testpi) devpi@x064:[/home/devpi/testpi]pip download -i  http://x064:8441/aixtools/dev cffi
Looking in indexes: http://x064:8441/aixtools/dev
Collecting cffi
  Downloading http://x064:8441/aixtools/dev/%2Bf/504/244e6fc36188b/cffi-1.12.3.tar.gz (452kB)
     |################################| 460kB 28.7MB/s
  Saved ./cffi-1.12.3.tar.gz
Collecting pycparser (from cffi)
  Downloading http://x064:8441/aixtools/dev/%2Bf/d9d/f2f3597ea75ab/pycparser-2.19-py2.py3-none-any.whl (111kB)
     |################################| 112kB 28.4MB/s
  Saved ./pycparser-2.19-py2.py3-none-any.whl
Successfully downloaded cffi pycparser

So, a wheel (for pycparser) and a .gz (for cffi).

Phase 2:

repeat the upload of cffi, but now from an AIX 7.1 server.

Preview:

(piserv) devpi@x064:[/home/devpi/testpi/cffi-1.12.3]devpi list pycparser
http://x064:8441/aixtools/dev/+f/d9d/f2f3597ea75ab/pycparser-2.19-py2.py3-none-any.whl
http://x064:8441/aixtools/dev/+f/2a8/90514e40f6d1c/pycparser-2.19.tar.gz
(piserv) devpi@x064:[/home/devpi/testpi/cffi-1.12.3]devpi list cffi
http://x064:8441/aixtools/dev/+f/53d/50f8d231592dc/cffi-1.12.3-cp37-cp37m-aix_6_1.whl
http://x064:8441/aixtools/dev/+f/504/244e6fc36188b/cffi-1.12.3.tar.gz
http://x064:8441/aixtools/dev/+f/4d2/0d8ee28c40fe7/cffi-1.12.3-cp37-cp37m-aix_7_1.whl

(testpi) devpi@x064:[/home/devpi/xyz]pip download -i  http://x064:8441/aixtools/dev cffi
Looking in indexes: http://x064:8441/aixtools/dev
Collecting cffi
  Downloading http://x064:8441/aixtools/dev/%2Bf/4d2/0d8ee28c40fe7/cffi-1.12.3-cp37-cp37m-aix_7_1.whl (197kB)
     |################################| 204kB 20.7MB/s
  Saved ./cffi-1.12.3-cp37-cp37m-aix_7_1.whl
Collecting pycparser (from cffi)
  Downloading http://x064:8441/aixtools/dev/%2Bf/d9d/f2f3597ea75ab/pycparser-2.19-py2.py3-none-any.whl (111kB)
     |################################| 112kB 23.3MB/s
  Saved ./pycparser-2.19-py2.py3-none-any.whl
Successfully downloaded cffi pycparser

Regards,
Michael