Bundle on CircleCI can't find new version of my gem

Hi,

I have a private project building on Circle CI, which depends on a public gem I maintain, acts_as_having_string_id. Whenever I release a new version of the gem, and make my private project depend on it, the Circle build fails (while it works perfectly on my local machine):

bundle check --path=vendor/bundle || bundle install --path=vendor/bundle --jobs=4 --retry=3 
Warning: the running version of Bundler (1.13.2) is older than the version that created the lockfile (1.13.4). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
Bundler can't satisfy your Gemfile's dependencies.
Install missing gems with `bundle install`.
Warning: the running version of Bundler (1.13.2) is older than the version that created the lockfile (1.13.4). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
Fetching gem metadata from https://rubygems.org/............
Fetching version metadata from https://rubygems.org/..
Fetching dependency metadata from https://rubygems.org/.
Could not find gem 'acts_as_having_string_id (~> 0.2.3)' in any of the gem
sources listed in your Gemfile or available on this machine.

bundle check --path=vendor/bundle || bundle install --path=vendor/bundle --jobs=4 --retry=3  returned exit code 7

Action failed: bundle install

I’ve tried rebuilding without cache to no avail.

I also tried SSH:ing to the machine, and running the failing command there fails in the exact same way. Showing remote versions of the gem on the machine works as expected:

$ gem list acts_as_having_string_id --remote

*** REMOTE GEMS ***

acts_as_having_string_id (0.2.3)

Also, installing the gem using gem install works.

What did work was specifying bundler version 1.13.4 in my circle.yml (basically what the warnings above suggested). And once it built the thing once, I could remove the version specification again.

Any idea what’s happening here? Surely, a revision difference of 2 shouldn’t matter?