2.0 builds failing on starting previously working docker image

Our previously working Circle 2.0 started repeatably failing on Friday (four days ago) and have not been working since. We get this output as part of the Spin Up Environment step:

Build-agent version 0.0.3822-e94be62 (2017-07-29T01:12:09+0000)
Starting container kairosaero/dkr-circleci
  image cache not found on this host, downloading kairosaero/dkr-circleci
latest: Pulling from kairosaero/dkr-circleci
e0a742c2abfd: Already exists
486cb8339a27: Already exists
dc6f0d824617: Already exists
4f7a5649a30e: Already exists
672363445ad2: Already exists
82945185d26a: Pulling fs layer
30e782536161: Pulling fs layer
3fcc56b87440: Pulling fs layer
dd8f46e8f49d: Pulling fs layer
8685d04cc7e5: Pulling fs layer
52f75a3acf18: Pulling fs layer
3f488794af1d: Pulling fs layer
b5924cf41a4b: Pulling fs layer
b3a3533a07da: Pulling fs layer
dd8f46e8f49d: Waiting
6967cc10c8a7: Pulling fs layer
8685d04cc7e5: Waiting
b5924cf41a4b: Waiting
b3a3533a07da: Waiting
6a13294e2cd3: Pulling fs layer
52f75a3acf18: Waiting
3f488794af1d: Waiting
c26345aa63ad: Pulling fs layer
2da6c462240b: Pulling fs layer
6ecdcbba76cc: Pulling fs layer
6a13294e2cd3: Waiting
c26345aa63ad: Waiting
6ecdcbba76cc: Waiting
2da6c462240b: Waiting
6967cc10c8a7: Waiting
82945185d26a: Verifying Checksum
82945185d26a: Download complete
dd8f46e8f49d: Verifying Checksum
dd8f46e8f49d: Download complete
30e782536161: Verifying Checksum
30e782536161: Download complete
52f75a3acf18: Verifying Checksum
52f75a3acf18: Download complete
8685d04cc7e5: Verifying Checksum
8685d04cc7e5: Download complete
82945185d26a: Pull complete
b5924cf41a4b: Download complete
b3a3533a07da: Download complete
6967cc10c8a7: Verifying Checksum
6967cc10c8a7: Download complete
6a13294e2cd3: Verifying Checksum
6a13294e2cd3: Download complete
3fcc56b87440: Verifying Checksum
3fcc56b87440: Download complete
2da6c462240b: Verifying Checksum
2da6c462240b: Download complete
c26345aa63ad: Verifying Checksum
c26345aa63ad: Download complete
6ecdcbba76cc: Download complete
30e782536161: Pull complete
3f488794af1d: Download complete
3fcc56b87440: Pull complete
dd8f46e8f49d: Pull complete
8685d04cc7e5: Pull complete
52f75a3acf18: Pull complete
3f488794af1d: Pull complete
b5924cf41a4b: Pull complete
b3a3533a07da: Pull complete
6967cc10c8a7: Pull complete
6a13294e2cd3: Pull complete
c26345aa63ad: Pull complete
2da6c462240b: Pull complete
6ecdcbba76cc: Pull complete
Digest: sha256:cd0cad0ac636921403d1a89ab80e8e3465907cc474d7a7de3fb5deb1446e8085
Status: Downloaded newer image for kairosaero/dkr-circleci:latest
  using image kairosaero/dkr-circleci@sha256:cd0cad0ac636921403d1a89ab80e8e3465907cc474d7a7de3fb5deb1446e8085
Error response from daemon: oci runtime error: container_linux.go:247: starting container process caused "exec: \".\": executable file not found in $PATH"

I’ve confirmed that this is not due to a change in our docker image (by trying previous versions).

Running the same image locally against docker 17.05 works great.

Our docker container is documented here: https://hub.docker.com/r/kairosaero/dkr-circleci/

If I had to guess, there was an upgrade to a docker component that is now choking on something in the image.

Any help or pointers would be appreciated - all of our 2.0 builds are currently broken because of this issue.

Still no solution, but after further research, it seems like maybe entrypoint in the circle config.yml is now using the exec form instead of the shell form (hence . not being an executable in the path - since it’s a shell built-in).