Re: 13.2 BETA2: how do debug META_MODE?

On Tue, Feb 21, 2023 at 11:56:13AM -0800, Mark Millard wrote:
! On Feb 21, 2023, at 04:55, Peter <pmc@citylink.dinoex.sub.org> wrote:
! 
! > ! # cd /usr/src/
! > ! # env WITH_META_MODE=yes make buildworld
! > ! # env WITH_META_MODE=yes make installworld
! > ! # env WITH_META_MODE=yes make buildworld (again #0)
! > ! ## no more rebuilds below?
! > ! # env WITH_META_MODE=yes make buildworld (again #1)
! > ! # env WITH_META_MODE=yes make buildworld (again #2)
! > 
! > But what is the difference between #0 and #1?
! 
! awk, cp, ln, rm, sed, and many more from
! . . ./tmp/legacy/usr/sbin/have new dates
! for rebuilds after installworld (that targets
! the running system). Not true for #1 and #2.
! 
! The dates on these tools being more recent than
! the files that they were involved in producing
! leads to rebuilding those files. That in turn
! leads to other files being rebuilt.
! 
! make with -dM reports the likes of:
! 
!    file '. . ./tmp/legacy/usr/sbin/awk' is newer than the target...
! 
! explicitly as it goes. As I remember tmp/legacy/usr/sbin/
! was always part of the path for what I found.

Mark, thanks a lot for the proper input at the right time!

This put me on the right track and I mananged to analyze and
understand what is actually happening.

It looks like my issue does resolve itself somehow, and things
start  to behave as expected again after four builds.

! I did not do the analysis of how (e.g.) tmp/legacy/usr/sbin/awk
! ended up being newer than such a target and, so, causing a
! rebuild of that target. I was going the direction: that
! it is newer really is unlikely to justify the rebuild for
! the target(s) in question. The other direction about how
! it got to be newer is also relevant.

I have now analyzed some parts of it. META_MODE typically finds some
build-tools to rebuild, but then if the result is not different
from what was there before, then "install" will not copy it to the
bin-dir, and so the avalanche gets usually avoided.