diff -up src/sage/databases/cremona.py.orig src/sage/databases/cremona.py
--- src/sage/databases/cremona.py.orig 2019-06-26 14:41:04.000000000 -0600
+++ src/sage/databases/cremona.py 2019-09-09 15:37:13.321511378 -0600
@@ -842,7 +842,8 @@ class MiniCremonaDatabase(SQLDatabase):
message = "There is no elliptic curve with label " \
+ label + " in the default database; try installing " \
+ "the optional package database_cremona_ellcurve which " \
- + "contains the complete Cremona database"
+ + "contains the complete Cremona database: " \
+ + "sudo dnf install sagemath-data-elliptic_curves_large"
raise ValueError(message)
ainvs = eval(c[0])
data = {'cremona_label': label,
@@ -1640,6 +1641,7 @@ class LargeCremonaDatabase(MiniCremonaDa
con.executemany("UPDATE t_curve SET gens=? WHERE curve=?", \
curve_data)
print("Committing...")
+ self.commit()
if largest_conductor and int(v[0]) > largest_conductor: break
_db = None