Getting value of MAKEOBJDIRPREFIX with 'make -V MAKEOBJDIRPREFIX'

Hello,

I'm writing shell script to build and install base system from source
and -V option of make(1) is used in it to get value of MAKEOBJDIRPREFIX.

By default it works fine with all of head, releng/11.2, releng/12.0,
stable/11 and stable/12.


yasu_at_eastasia[2389]% svn info /usr0/freebsd/base/head
Path: /usr0/freebsd/base/head
Working Copy Root Path: /usr0/freebsd/base/head
URL: https://svn.freebsd.org/base/head
Relative URL: ^/head
Repository Root: https://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 340474
Node Kind: directory
Schedule: normal
Last Changed Author: karels
Last Changed Rev: 340474
Last Changed Date: 2018-11-16 12:42:29 +0900 (Fri, 16 Nov 2018)

yasu_at_eastasia[2390]% make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/head
/usr/obj
yasu_at_eastasia[2391]% svn info /usr0/freebsd/base/releng/11.2
Path: /usr0/freebsd/base/releng/11.2
Working Copy Root Path: /usr0/freebsd/base/releng/11.2
URL: https://svn.freebsd.org/base/releng/11.2
Relative URL: ^/releng/11.2
Repository Root: https://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 338990
Node Kind: directory
Schedule: normal
Last Changed Author: gordon
Last Changed Rev: 338981
Last Changed Date: 2018-09-28 03:36:30 +0900 (Fri, 28 Sep 2018)

yasu_at_eastasia[2392]% make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/releng/11.2
/usr/obj
yasu_at_eastasia[2393]% svn info /usr0/freebsd/base/releng/12.0
Path: /usr0/freebsd/base/releng/12.0
Working Copy Root Path: /usr0/freebsd/base/releng/12.0
URL: https://svn.freebsd.org/base/releng/12.0
Relative URL: ^/releng/12.0
Repository Root: https://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 340471
Node Kind: directory
Schedule: normal
Last Changed Author: gjb
Last Changed Rev: 340470
Last Changed Date: 2018-11-16 09:00:59 +0900 (Fri, 16 Nov 2018)

yasu_at_eastasia[2394]% make -C /usr0/freebsd/base/releng/12.0 -V MAKEOBJDIRPREFIX
/usr/obj
yasu_at_eastasia[2395]% svn info /usr0/freebsd/base/stable/11
Path: /usr0/freebsd/base/stable/11
Working Copy Root Path: /usr0/freebsd/base/stable/11
URL: https://svn.freebsd.org/base/stable/11
Relative URL: ^/stable/11
Repository Root: https://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 340473
Node Kind: directory
Schedule: normal
Last Changed Author: ygy
Last Changed Rev: 340449
Last Changed Date: 2018-11-15 17:43:17 +0900 (Thu, 15 Nov 2018)

yasu_at_eastasia[2396]% make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/stable/11
/usr/obj
yasu_at_eastasia[2397]% svn info /usr0/freebsd/base/stable/12
Path: /usr0/freebsd/base/stable/12
Working Copy Root Path: /usr0/freebsd/base/stable/12
URL: https://svn.freebsd.org/base/stable/12
Relative URL: ^/stable/12
Repository Root: https://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 340474
Node Kind: directory
Schedule: normal
Last Changed Author: gjb
Last Changed Rev: 340471
Last Changed Date: 2018-11-16 09:03:31 +0900 (Fri, 16 Nov 2018)

yasu_at_eastasia[2398]% make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/stable/12
/usr/obj


But if I customize value of MAKEOBJDIRPREFIX then it still works with
releng/11.2 and stable/11 but doesn't with head, releng/12.0 and stable/12.


yasu_at_eastasia[2399]% env MAKEOBJDIRPREFIX=/usr0/freebsd/base/ogj make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/head

yasu_at_eastasia[2400]% env MAKEOBJDIRPREFIX=/usr0/freebsd/base/ogj make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/releng/11.2
/usr0/freebsd/base/ogj
yasu_at_eastasia[2401]% env MAKEOBJDIRPREFIX=/usr0/freebsd/base/ogj make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/releng/12.0

yasu_at_eastasia[2402]% env MAKEOBJDIRPREFIX=/usr0/freebsd/base/ogj make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/stable/11
/usr0/freebsd/base/ogj
yasu_at_eastasia[2403]% env MAKEOBJDIRPREFIX=/usr0/freebsd/base/ogj make -V MAKEOBJDIRPREFIX -C /usr0/freebsd/base/stable/12

yasu_at_eastasia[2404]%


I used env(1) to customize but I got same results when I use
src-env.conf.

Then is this just bug? Or are there any reason that behavior is
changed from 11.x to 12.x and later?

Best Regards.

---
Yasuhiro KIMURA