Bug 11641

Summary:	linux kernel .config timestamp always out of date fixed with KCONFIG_NOSILENTUPDATE
Product:	buildroot	Reporter:	Doug Crawford <dcraw101>
Component:	Other	Assignee:	unassigned
Status:	RESOLVED FIXED
Severity:	normal	CC:	buildroot
Priority:	P5
Version:	2018.11.1
Target Milestone:	---
Hardware:	All
OS:	Linux
Host:		Target:
Build:

Description Doug Crawford 2019-01-24 16:33:26 UTC

Just noticed this when migrating from kernel 4.9 to 4.19.  I noticed that now in the linux kernel build dir the .config timestamp is always later than the .stamp_kconfig_fixup_done.  So every incremental buildroot make causes the kernel build to always run starting at the kconfig fixup phase.

I traced the problem to somewhere in the kernel syncconfig step in the kernel "build" phase.  I think it is related to this new kernel 4.19 commit.

16952b77d8 kconfig: make syncconfig update .config regardless of sym_change_count

If I define KCONFIG_NOSILENTUPDATE in my environment the problem goes away and the timestamps are correct.  Should buildroot set this env variable?  I am not sure what the other side affects would be.

Comment 1 Thomas Petazzoni 2019-08-15 13:19:29 UTC

Thanks for your bug report! This was fixed by commit https://git.buildroot.org/buildroot/commit/?id=05fea6e4a60a38a797d9bacbf318a2cd7dbd435f.