Problems with --read-only on CircleCI

[Chris Gorgolewski]

Dear all,

We recently discovered a bug in Docker implementation used on CircleCI: the --read-only flag is being ignored silently. I have reported the problem to CircleCI (https://discuss.circleci.com/t/circlecis-docker-implementations-silently-ignore-read-only-flag/6350 - you can help by upvoting it or making a comment) and hopefully it will resolved soon. In the meantime in addition to CircleCI please test your apps locally (with the --read-only flags) to make sure that they will still work correctly after conversion to singularity.

Best,

Chris

PS I also investigated switching to Travis - it's possible and the --read-only flag works as expected on travis. The problem is that Travis is slower, provides less HDD space (not enough to cache the bigger container images) and as bigger limitations on running time (max is 50 min for all tests combined). Let's see if Circle can fix the bug.