cbuildbot: run verifybinpkg with the --update flag

When upgrading a package that triggers subslot rebuilds, emerge might
abort due to blockers that the library has in place.  For example with
the ncurses update which moves from SLOT=0/5 to SLOT=0/6, and includes
a blocker on SLOT=0/5, emerge aborts because it doesn't flag all the
packages for upgrading (so some existing packages keep depending on the
old SLOT=0/5).  Adding an explicit --update allows portage to load all
the packages it needs to.

For example:
$ emerge-eve -pegNvq '--with-bdeps=y' '--color=n' virtual/target-os \
	virtual/target-os-dev virtual/target-os-test virtual/target-os-factory \
	virtual/target-os-factory-shim chromeos-base/autotest-all
...
[binary   R   ] sys-power/powertop-2.8-r1 to /build/eve/
[binary   R   ] app-editors/vim-7.4.712 to /build/eve/
[binary   R   ] sys-libs/ncurses-5.9-r5 to /build/eve/
[ebuild     U ] sys-libs/ncurses-5.9-r101 [5.9-r99] to /build/eve/
...
[blocks B     ] <sys-libs/ncurses-6:0 ("<sys-libs/ncurses-6:0" is blocking sys-libs/ncurses-5.9-r101)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  (sys-libs/ncurses-5.9-r5:0/5::portage-stable, binary scheduled for merge to '/build/eve/') pulled in by
    >=sys-libs/ncurses-5.2-r2 required by (app-editors/vim-7.4.712:0/0::portage-stable, binary scheduled for merge to '/build/eve/')
    ...
  (sys-libs/ncurses-5.9-r101:5/5::portage-stable, ebuild scheduled for merge to '/build/eve/') pulled in by
    sys-libs/ncurses:5/5= required by (sys-power/powertop-2.8-r1:0/0::portage-stable, binary scheduled for merge to '/build/eve/')
    ...

By adding the --update flag, portage will allow these to be rebuilt:
[ebuild  N    ] sys-libs/ncurses-6.0-r2 to /build/eve/
[ebuild  N    ] sys-libs/ncurses-5.9-r101 to /build/eve/

BUG=chromium:800049
TEST=precq passes

Change-Id: Idc9c8d87794555bd2db30294dcddd3ff6ce33c14
Reviewed-on: https://chromium-review.googlesource.com/858197
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
1 file changed