RuntimeError: nlopt failure

[rezah]

I get an error: RuntimeError: nlopt failure

File "/home/reza/anaconda3/envs/qdev/lib/python3.9/site-packages/nlopt/nlopt.py", line 334, in optimize return _nlopt.opt_optimize(self, *args) RuntimeError: nlopt failure

even by setting opt.set_maxtime(-1)

[jschueller]

please provide a minimal script

[rezah]

Well, I can not provide a minimal example, as it is used with other packages. It works well in so many cases (so grad is calculated right) but only in few cases do I face this problem. I use LD_LBFGS

Also the same code using scipy "L-BFGS-B" works well.

[jschueller]

at least provide something to reproduce, else we cannot help you