Whenever I set the cell with
import pdb
pdb.set_trace()
a = 100
inside a jupyter notebook, tracer will get into the set_trace() method with n instead the next line.
I don't know what to do? How can I get the next line a = 100.
To be worse even jump to that line with j provides error:
*** Jump failed: can only jump from a 'line' trace event
This is post-mortem mode of pdb/ipdb. Commands like jump, next, step, return are not available because the script is no longer running.
The post-mortem mode is for intercepting unhandled exceptions and inspecting the program state whenever such exception is raised, without having to sprinkle the code with pdb.set_trace() (or simply breakpoint() since python 3.7).Can be easily provoked by something like print(a) without defining a or the classical division by zero 1/0.
The continue command, shorthand c, is kind-of available in the post-mortem mode but what it really does in such mode is it causes pdb/ipdb to finish the post-mortem, reload the file, and restart the script with any breakpoints, shorthand b, e.g. b 20 for line 20, you might have prepared during the post-mortem.
See also this answer to a similar question.
As Steven Kryscala on codementor says:
When pdb says it will restart the program, or when you use the restart command, code changes to the script you're debugging will be reloaded automatically. Breakpoints will still be set after reloading, but may need to be cleared and re-set due to line numbers shifting. Code changes to other imported modules will not be reloaded — you will need to quit and re-run the -mpdb command to pick those up.
Used the option b like b 20 of the debugger to set a breakpoint and this way I escaped from the get_trace, just after c (continue).
I will gladly accept proper solution for this problem.