I'll take a look.

Take chromeos2-row8-rack8-host11 for example, it was running tests for R62 build when R64 build required for duts. There're 6 wizpig duts in pvt in total, if another release build uses some, it's possible R64 will run out of duts.

http://cautotest/afe/#tab_id=view_job&object_id=150147128
Job: wizpig-release/R62-9901.50.0/paygen_au_stable/autoupdate_EndToEndTest_paygen_au_stable_delta_9334.72.0 (150147128-chromeos-test)



https://uberchromegw.corp.google.com/i/chromeos_release/builders/wizpig-release%20release-R62-9901.B/builds/46

just moved 2 duts from suites to bvt


before:

atest host list -b board:wizpig  | grep bvt | wc -l
6

atest host list -b board:wizpig  | grep pool:suites | wc -l
10

after:

nxia@nxia:~/chrome_infra/build$ atest host list -b board:wizpig  | grep pool:suites | wc -l
8
nxia@nxia:~/chrome_infra/build$ atest host list -b board:wizpig  | grep pool:bvt | wc -l
8

NotEnoughDutsError was threw as expected. now wizpig has 8 duts in pvt which will allows 2 release builds running tests at the same time, but when a third release build kick in, this error can still show up. closing this bug as it works as expected.