diff --git a/lib/spack/spack/reporters/cdash.py b/lib/spack/spack/reporters/cdash.py
index e27d7e9728e43e3f17a646d92f4d0349d22221da..7093afa2ef2702f4a58fd47fe6231c326408002c 100644
--- a/lib/spack/spack/reporters/cdash.py
+++ b/lib/spack/spack/reporters/cdash.py
@@ -77,6 +77,7 @@ def build_report(self, filename, report_data):
 
         # Parse output phase-by-phase.
         phase_regexp = re.compile(r"Executing phase: '(.*)'")
+        cdash_phase = ''
         for spec in report_data['specs']:
             for package in spec['packages']:
                 if 'stdout' in package: