client.timer failed on AArch64 Jenkins

client.timer failed once on Jenkins:

http://jenkins.dynamorio.org:8080/job/DynamoRIO-AArch64-Postcommit/310/console

04:04:02         Start  97: code_api|client.timer
...
04:04:02 100/172 Test  #97: code_api|client.timer ...........................***Failed  Required regular expression not found.Regex=[^(client event_timer fired
04:04:02 )+(app got SIGALRM
04:04:02 )+(client event_timer fired
04:04:02 )+.*
04:04:02 $
04:04:02 ]  1.64 sec
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 app got SIGALRM
04:04:02 
04:04:02         Start 100: code_api|client.emulation_api_simple