[Toybox] FYI: kernel builds rely on GNU expr extensions

[Rob Landley]

On 5/2/19 4:20 PM, enh wrote:
> (fwiw, with an instrumented build of the 4.19 Android common kernel, i
> only see `expr 4 * 65536 + 019 * 256 + 037`. so i don't know what
> they're _really_ doing to hit this.)

Back under Aboriginal Linux what I'd do is prepare two parallel package build
folders, one with the new environment and one with the old environment, then run
a UP build with "2>&1 | tee out.txt" (no parallelism so no log jitter and where
it stops is the first time it noticed the problem), then rename that directory
and name the second directory in its place (so both builds have the same
absolute path to reduce log diff) and build the other one, and then diff both
entire trees and swear about all the false positives caused by the clock
changing and that making its way into binary output and/or logs. Oh, and V=1 in
kernel builds, obviously...

This sort of thing was often a multi-day dig. I need to build up mkroot so it's
building as many things as aboriginal linux used to, but have yet to circle my
way back around to that...

Where's the git repo and .config for this kernel they're trying to build when
they hit this?

Rob

P.S. Yeah, I should start the Giant AOSP download onto the new machine when I
get back to the cable modem after lunch. 16 gigs ram and 2 terabyte drive,
should _finally_ have space for it. Only an i5-3340M processor though, It's 2X
SMP @2.7 ghz hyperthreaded to 4X, probably a 24 hour build time for the whole
image...