`uname -a' can't display revision

[KIRIYAMA Kazuhiko]

On Tue, 20 Aug 2019 13:47:55 +0900,
Trond Endrestøl wrote:
> 
> On Tue, 20 Aug 2019 11:00+0900, KIRIYAMA Kazuhiko wrote:
> 
> > I've rebuild up to r351108 but `uname -a' can't display it's
> > revision number. 
> 
> Add this to /etc/src.conf:
> 
> WITHOUT_REPRODUCIBLE_BUILD=yes

Add above and rebuild with r351247, then

admin at tbedfs:~ % uname -a
FreeBSD tbedfs 12.0-STABLE FreeBSD 12.0-STABLE #0: Tue Aug 20 19:10:53 JST 2019     root at tbedfs:/usr/obj/usr/src/amd64.amd64/sys/GENERIC  amd64
admin at tbedfs:~ % 

Only revision number ommitted. Why ?

Regards.
---
KIRIYAMA Kazuhiko