sh: 1: set: Illegal option -o pipefail

Today after I updated to gitlab-ci-multi-runner 1.1.0 (a23a25a) all my builds started failing with this error:

gitlab-ci-multi-runner 1.1.0 (a23a25a)
Using Docker executor with image lynxsolutions/docker-composer-npm-bower-gulp ...
Pulling docker image lynxsolutions/docker-composer-npm-bower-gulp ...

Running on runner-d31c18f8-project-117-concurrent-0 via 2e4c6d657b1f...
Fetching changes...
HEAD is now at 9913835 Merge branch 'develop' of <repo> into develop
Checking out 99138350 as staging...
HEAD is now at 9913835... Merge branch 'develop' of <repo> into develop

sh: 1: set: Illegal option -o pipefail

ERROR: Build failed: exit code 2

Note: builds use the docker executor, and worked fine yesterday with gitlab-ci-multi-runner 1.0.4 (014aa8c)

Any ideas guys?