Run eigen_assert on CI runs.

Change-Id: I1cc7cc592dc561a5d9a1d00b2a5ace5087ebd2db
diff --git a/.bazelrc b/.bazelrc
index c80339f..57f01ea 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -50,6 +50,10 @@
 build:msan --test_env MSAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer-3.6
 build:msan --define have_msan=true
 
+# Sometime, we want to be able to have eigen assertions run so that we can
+# catch potential issues (e.g., accessing invalid indices).
+build:eigen  --copt -UNDEBUG
+
 # Show paths to a few more than just 1 target.
 build --show_result 5
 # Dump the output of the failing test to stdout.
diff --git a/tools/ci/run-tests.sh b/tools/ci/run-tests.sh
index e0e7bb6..91fbb2d 100755
--- a/tools/ci/run-tests.sh
+++ b/tools/ci/run-tests.sh
@@ -4,7 +4,9 @@
 
 TARGETS='//... @com_github_google_glog//... @com_google_ceres_solver//...'
 
-bazel test -c opt --curses=no --color=no ${TARGETS}
+# Include --config=eigen to enable Eigen assertions so that we catch potential
+# bugs with Eigen.
+bazel test -c opt --config=eigen --curses=no --color=no ${TARGETS}
 bazel build -c opt --curses=no --color=no ${TARGETS} --cpu=roborio
 bazel build --curses=no --color=no ${TARGETS} --cpu=armhf-debian
 bazel build -c opt --curses=no --color=no //motors/... --cpu=cortex-m4f