heuristically prevent infinite loop

6 jobs for cgg in 7 minutes and 54 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #81224
Linux
clang-c++11

00:06:44

passed #81226
Linux
clang-c++14

00:07:52

passed #81223
Linux
gcc-c++11

00:02:31

passed #81225
Linux
gcc-c++14

00:02:20

passed #81227
Apple
macos-c++11

00:05:18

passed #81228
Apple
macos-c++14

00:02:57