When a baseline fails to be created, the promotion level of the previous baseline is being set to REJECTED. If a baseline is not created, then the promotion level should/can not be changed. See below:

Created baseline "I-TEST-CI-148" in component "test_comp".
Begin incrementally labeling baseline "I-TEST-CI-148".
cleartool: Error: Version map for baseline "R-TEST-CI-186" is unavailable.
cleartool: Error: Error incrementally labeling baseline "I-TEST-CI-148".
cleartool: Warning: Some of stream "test_CI"'s latest baselines are not labeled
Unlabeled baselines can't be recommended and can't be rebased to.
Use "cleartool chbl -incremental <baseline-selector>" to label these baselines:
I-TEST-CI-148 (component test_comp)
cleartool: Error: Could not label one or more baselines in stream "test_CI".
cleartool: Error: Unable to create baselines.
FATAL: UCM ClearCase failed. exit code=1
Failed to create baseline: java.io.IOException: cleartool did not return the expected exit code. Command line="mkbl -identical -comment I-TEST-CI-148 -full -view TEST-CI -comp test_comp@/vob I-TEST-CI-148", actual exit code=1
[WARNINGS] Skipping publisher since build result is FAILURE
[workspace] $ /opt/rational/clearcase/bin/cleartool chbl -c "Hudson set baseline to promotion level REJECTED" -level REJECTED I-TEST-CI-147@/vob
Changed baseline "I-TEST-CI-147".