First Build of OpenWrt for 8Devices Mango Fails

I'm following the procedure outlined by 8devices

My build environment is Ubuntu 20.04, 64 bit.

After installing, my first step is to build the basic image:

./ 8dev_mango_stripped -c

This results in the following error:

||| make[3] -C tools/flock install|
|||make -r world: build failed. Please re-run make with -j1 V=s to see what's going on|
|||make: *** [/home/tim/openwrt-8devices/include/ world] Error 1|

As suggested, I ran: make -j1 V=s
and got the following:

--------snip - lots of normal looking output  ---------
mv -f $depbase.Tpo $depbase.Po
freadahead.c: In function 'freadahead':
freadahead.c:91:3: error: #error "Please port gnulib freadahead.c to your platform! Look at the definitio             n of fflush, fread, ungetc on your system, then report this to bug-gnulib."
   91 |  #error "Please port gnulib freadahead.c to your platform! Look at the definition of fflush, frea             d, ungetc on your system, then report this to bug-gnulib."
      |   ^~~~~
make[7]: *** [Makefile:1837: freadahead.o] Error 1
make[7]: Leaving directory '/home/tim/openwrt-8devices/build_dir/host/m4-1.4.17/lib'
make[6]: *** [Makefile:1602: all] Error 2
make[6]: Leaving directory '/home/tim/openwrt-8devices/build_dir/host/m4-1.4.17/lib'
make[5]: *** [Makefile:1506: all-recursive] Error 1
make[5]: Leaving directory '/home/tim/openwrt-8devices/build_dir/host/m4-1.4.17'
make[4]: *** [Makefile:1461: all] Error 2
make[4]: Leaving directory '/home/tim/openwrt-8devices/build_dir/host/m4-1.4.17'
make[3]: *** [Makefile:29: /home/tim/openwrt-8devices/build_dir/host/m4-1.4.17/.built] Error 2
make[3]: Leaving directory '/home/tim/openwrt-8devices/tools/m4'
make[2]: *** [tools/Makefile:125: tools/m4/compile] Error 2
make[2]: Leaving directory '/home/tim/openwrt-8devices'
make[1]: *** [tools/Makefile:123: /home/tim/openwrt-8devices/staging_dir/target-arm_cortex-a7_musl-1.1.16             _eabi/stamp/.tools_install_yynyynynynyyyyyyyyynyyyyyyyyynyyyyynnyynnyynnnyy] Error 2
make[1]: Leaving directory '/home/tim/openwrt-8devices'
make: *** [/home/tim/openwrt-8devices/include/ world] Error 2

I'm not sure how to interpret "Please port gnulib freadahead.c to your platform!"
Why would that be missing in Ubuntu 20.04?
Can anyone provide suggestions?

Ask help from 8devices, as you are not compiling regular OpenWrt, but their proprietary version of it. ( Looks to be pretty old based on musl version)

If is old source code, you might need a buildhost from the same period (so that host tools match the expectations of the source). Try e.g. Ubuntu 16.04 that they seem to advice for...

I will reach out to 8devices.

However, I'm concerned that an old buildhost might be problematic for my goal which is to incorporate the latest iwlwifi drivers that include support for the AX-210. It is very recent

8devices is unwilling to assist, other than as a paid contracting job.

The the Mango is old source. I was able to build it in a Ubuntu 16.04 VM, but that doesn't help with the integrating the latest Intel iwlwifi driver.

The Intel AX-210 is supported in Kernel 5.11.

Attempting to upgrade the Mango OpenWrt version to work with kernel 5.11, or backporting iwlwifi to work with the Mango both seem like excessively difficult tasks.

I'm not even sure if iwlwifi is able to run on ARM based CPU - has anyone successfully used an Intel Wi-Fi adapter on an ARM platform?