cros_workon_make: Do not fail on first run.

cros_workon_make just after emerge (or build_packages) will cause an error:

sed: can't read /build/volteer/tmp/portage/chromeos-base/debugd-9999/temp/environment: No such file or directory

Skip patching the environment file when it doesn't exist.

BUG=chromium:1212997
TEST=FEATURES="test" emerge-volteer debugd && \
  cros_workon_make --test --board=volteer debugd
  # says WARN: Forcing reinitialization for the first time
  # instead.

Change-Id: I5f79931eb658556faa04cf5e79b7a02302015989
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/2929803
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Junichi Uekawa <uekawa@chromium.org>
Tested-by: Junichi Uekawa <uekawa@chromium.org>
1 file changed