[PATCH] Build error with buildworld and -j1 on a memory backed /usr/obj

[M. Warner Losh]

In message: <AANLkTildcwTnUiCNReWDoCm9Hf9d1JEmV4t4K-40HYSC at mail.gmail.com>
            Garrett Cooper <yanefbsd at gmail.com> writes:
:     The build for r209530 failed with a clean workspace and a clean
: /usr/obj/scratch. I was building with a memory-disk backed /usr/obj.
: Here's the error:
: 
: ===> usr.bin/ar (depend)
: lex -t  /scratch/freebsd/current/usr.bin/ar/acplex.l > acplex.c
: yacc -d /scratch/freebsd/current/usr.bin/ar/acpyacc.y
: cp y.tab.c acpyacc.c
: rm -f .depend
: mkdep -f .depend -a    -I. -I/scratch/freebsd/current/usr.bin/ar
: /scratch/freebsd/current/usr.bin/ar/ar.c acplex.c acpyacc.c
: /scratch/freebsd/current/usr.bin/ar/read.c
: /scratch/freebsd/current/usr.bin/ar/util.c
: /scratch/freebsd/current/usr.bin/ar/write.c
: /scratch/freebsd/current/usr.bin/ar/ar.c:66:21: error: archive.h: No
: such file or directory
: /scratch/freebsd/current/usr.bin/ar/acpyacc.y:35:21: error: archive.h:
: No such file or directory
: /scratch/freebsd/current/usr.bin/ar/acpyacc.y:36:27: error:
: archive_entry.h: No such file or directory
: /scratch/freebsd/current/usr.bin/ar/read.c:33:21: error: archive.h: No
: such file or directory
: /scratch/freebsd/current/usr.bin/ar/read.c:34:27: error:
: archive_entry.h: No such file or directory
: /scratch/freebsd/current/usr.bin/ar/write.c:34:21: error: archive.h:
: No such file or directory
: /scratch/freebsd/current/usr.bin/ar/write.c:35:27: error:
: archive_entry.h: No such file or directory
: mkdep: compile failed
: *** Error code 1
: 
: Stop in /scratch/freebsd/current/usr.bin/ar.
: *** Error code 1
: 
: Stop in /scratch/freebsd/current/usr.bin.
: *** Error code 1
: 
: Stop in /scratch/freebsd/current.
: *** Error code 1
: 
: Stop in /scratch/freebsd/current.
: *** Error code 1
: 
: Stop in /scratch/freebsd/current.
: 
:     I think this is due to dependency issues with libarchive. I had
: some changes in my p4 workspace to address the libarchive dependency
: for libpkg (for work that's incoming in the next couple of months)
: that Warner helped me out with, and once I applied the change things
: worked. The patch is attached.

This patch is contaminated with other patches.

Warner