Getting invalid option: --format Test::Unit automatic runner, causing run to be marked as failed

Rails: 3.2.22
Cucumber: 1.3.18

When my tests all pass, CircleCi is still marking them as failed, because Cucumber is finishing with the following statements:
277 scenarios (277 passed)
1836 steps (1836 passed)
14m27.871s
invalid option: --format
Test::Unit automatic runner.
Usage: /home/ubuntu/classroomparent/vendor/bundle/ruby/2.1.0/bin/cucumber [options] [-- untouched arguments]
-r, --runner=RUNNER Use the given RUNNER.
(c[onsole], e[macs], x[ml])
–collector=COLLECTOR Use the given COLLECTOR.
(de[scendant], di[r], l[oad], o[bject]_space)
-n, --name=NAME Runs tests matching NAME.
Use ‘/PATTERN/’ for NAME to use regular expression.
–ignore-name=NAME Ignores tests matching NAME.
Use ‘/PATTERN/’ for NAME to use regular expression.
-t, --testcase=TESTCASE Runs tests in TestCases matching TESTCASE.
Use ‘/PATTERN/’ for TESTCASE to use regular expression.
–ignore-testcase=TESTCASE Ignores tests in TestCases matching TESTCASE.
Use ‘/PATTERN/’ for TESTCASE to use regular expression.
–location=LOCATION Runs tests that defined in LOCATION.
LOCATION is one of PATH:LINE, PATH or LINE
–attribute=EXPRESSION Runs tests that matches EXPRESSION.
EXPRESSION is evaluated as Ruby’s expression.
Test attribute name can be used with no receiver in EXPRESSION.
EXPRESSION examples:
!slow
tag == ‘important’ and !slow
–[no-]priority-mode Runs some tests based on their priority.
–default-priority=PRIORITY Uses PRIORITY as default priority
(h[igh], i[mportant], l[ow], m[ust], ne[ver], no[rmal])
-I, --load-path=DIR[:DIR…] Appends directory list to $LOAD_PATH.
–color-scheme=SCHEME Use SCHEME as color scheme.
(d[efault])
–config=FILE Use YAML fomat FILE content as configuration file.
–order=ORDER Run tests in a test case in ORDER order.
(a[lphabetic], d[efined], r[andom])
–max-diff-target-string-size=SIZE
Shows diff if both expected result string size and actual result string size are less than or equal SIZE in bytes.
(1000)
–[no-]stop-on-failure Stops immediately on the first non success test
(false)
-v, --verbose=[LEVEL] Set the output level (default is verbose).
(important-only, n[ormal], p[rogress], s[ilent], v[erbose])
–[no-]use-color=[auto] Uses color output
(default is auto)
–progress-row-max=MAX Uses MAX as max terminal width for progress mark
(default is auto)
–no-show-detail-immediately Shows not passed test details immediately.
(default is yes)
–output-file-descriptor=FD Outputs to file descriptor FD
– Stop processing options so that the
remaining options will be passed to the
test.
-h, --help Display this help.

    Deprecated options:
            --console                    Console runner (use --runner).


    ((bundle exec cucumber "--format CircleCICucumberFormatter::CircleCIJson --out /tmp/circle-junit.KsAqmSb/cucumber/cucumber.cucumber" "")) returned exit code 1

This is my cucumber.yml file

<%
rerun = File.file?('rerun.txt') ? IO.read('rerun.txt') : ""
rerun_opts = rerun.to_s.strip.empty? ? "--format #{ENV['CUCUMBER_FORMAT'] || 'progress'} features" : "--format #{ENV['CUCUMBER_FORMAT'] || 'pretty'} #{rerun}"
std_opts = "--format #{ENV['CUCUMBER_FORMAT'] || 'progress'} --tags ~@wip"
%>
default: <%= std_opts %> features
wip: --tags @wip:3 --wip features
rerun: <%= rerun_opts %> --format rerun --out rerun.txt --strict --tags ~@wip

Any help/advice is greatly appreciated.