Cbc cannot process generated LP file about rust-lp-modeler HOT 4 CLOSED

cbc test.lp

$ cbc test.lp
Welcome to the CBC MILP Solver 
Version: 2.8.12 
Build Date: Sep  3 2014 

command line - cbc test.lp (default strategy 1)
Coin0009I  CoinLpIO::readLp(): Maximization problem reformulated as minimization
Coin3007W ### CoinLpIO::is_invalid_name(): Name is empty
Coin3007W ### CoinLpIO::are_invalid_names(): Invalid name: vnames[3]: (null)
Coin3007W ### CoinLpIO::setLpDataRowAndColNames(): Invalid row names
Use getPreviousNames() to get the old row names.
Now using default row names.
Continuous objective value is 0 - 0.00 seconds
Cgl0004I processed model has 0 rows, 0 columns (0 integer) and 0 elements
Cbc3007W No integer variables - nothing to do
Cuts at root node changed objective from 0 to -1.79769e+308
Probing was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)
Gomory was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)
Knapsack was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)
Clique was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)
MixedIntegerRounding2 was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)
FlowCover was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)
TwoMirCuts was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds)

Result - Optimal solution found

Objective value:                0.00000000
Enumerated nodes:               0
Total iterations:               0
Time (CPU seconds):             0.00
Time (Wallclock seconds):       0.01

Total time (CPU seconds):       0.00   (Wallclock seconds):       0.02