Rebuild Portage cache with the --regen command

This command is smarter than egencache and will populate the edb cache
or validate that the md5-cache entries are up to date as needed. This
command only writes to the edb cache if entries are stale and so will
not dirty the git tree.

BUG=chromium:1017395
TEST=`update_chroot`

Change-Id: I3dd34418abed7de9dbd6143e830e4ce2cd188933
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/1900320
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Will Bradley <wbbradley@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed