It's observed for more than a week, and spotted for both precise_cloud slaves (subjectively happens more frequently), and precise_cloud. E.g.:
https://ci.linaro.org/jenkins/computer/i-81cd9be5/log (will likely become unavailable as URL later, but accessible on FS):
Get:49 http://archive.ubuntu.com oneiric-updates/restricted Translation-en [508 B]
Get:50 http://archive.ubuntu.com oneiric-updates/universe Translation-en [62.9 kB]
Fetched 17.1 MB in 11s (1517 kB/s)
Reading package lists...
+ apt-get install --force-yes -y default-jre
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package default-jre
Verifying that java exists
bash: java: command not found
https:/ /ci.linaro. org/jenkins/ computer/ i-911041f5/ log
Get:33 http:// archive. ubuntu. com precise- updates/ restricted Translation-en [14 B] archive. ubuntu. com precise- updates/ universe Translation-en [14 B]
Get:34 http://
Fetched 16.8 MB in 8s (2072 kB/s)
Reading package lists...
+ apt-get install --force-yes -y default-jre
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package default-jre
Verifying that java exists
bash: java: command not found