print more on exercise check failure

7 jobs for master in 3 minutes and 49 seconds (queued for 4 seconds)
Name Stage Failure
failed
build-coq.8.10.1 Build
Makefile.coq.local:14: recipe for target 'ci' failed
make[1]: *** [ci] Error 1
Makefile:6: recipe for target 'ci' failed
make: *** [ci] Error 2

real 0m21.020s
user 1m58.520s
sys 0m6.788s
ERROR: Job failed: exit code 1