tests: try multiple times to get a database name

tests/utilities.py

@@ -145,11 +145,21 @@ def create_temporary_pub(sql_mode=False, templates_mode=False, lazy_mode=False):
     if sql_mode:
         conn = psycopg2.connect(user=os.environ['USER'])
         conn.set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
-        cur = conn.cursor()
-        dbname = 'wcstests%d' % random.randint(0, 100000)
-        known_elements.sql_db_name = dbname
-        cur.execute('CREATE DATABASE %s' % dbname)
-        cur.close()
+        i = 0
+        while True:
+            dbname = 'wcstests%d' % random.randint(0, 100000)
+            known_elements.sql_db_name = dbname
+            try:
+                cur = conn.cursor()
+                cur.execute('CREATE DATABASE %s' % dbname)
+                break
+            except psycopg2.Error as e:
+                if i < 5:
+                    i += 1
+                    continue
+                raise
+            finally:
+                cur.close()
 
         pub.cfg['postgresql'] = {'database': dbname, 'user': os.environ['USER']}
         pub.write_cfg()