Which version of Devel::NYTProf are you using? And are you able to provide a cut-down script that can reproduce the issue?

Looking at the code, you might also be able to patch the issue by checking that $self->profile can call the inc method before it is called. You could then perhaps munge the name yourself and see what happens to the report.

I can't provide a sscce because it's a very large module. I was using 6.05 but upgraded to 6.06 after your inquiry. It still fails with the same errors except one minor difference I don't understand (2695 -> 2698):

collapse_sibling_evals: nested evals in (eval 2695)
collapse_sibling_evals: nested evals in (eval 2698)

Debugging nytprof is over my head but I can see from the comments around line 430 in /Devel/NYTProf/FileInfo.pm that someone anticipated problems. How would you patch this?

# Should return the filename that the application used when loading th
+e file
# For evals should remove the @INC portion from within the "(eval N)[$
+path]"
# and similarly for Class::MOP #line evals "... defined at $path".
# This is a bit of a fudge. Filename handling should be improved in th
+e profiler.
sub filename_without_inc {
    my $self = shift;
    my $f    = [$self->filename];
    strip_prefix_from_paths([$self->profile->inc], $f, # line 430
        qr/(?: ^ | \[ | \sdefined\sat\s )/x
    );
    return $f->[0];
}
[download]

The first thing I would try is to avoid the inc call, which is what bliako does in 11114118.

It is probably worth instrumenting the code block with print statements to see what happens in this code under normal circumstances for a simplified script with nested evals. Or you could use the debugger if you are familiar with it or have access to one through an IDE.

(Edit 20201303 - use code, not para, tags for "inc".)

What does the error mean? What is undefined? Is my code causing the issue or is something wrong with NYTProf?

One thing is sure, $self->profile returns undef. Just a wild guess: strip_prefix_from_paths() removes the ABC::XYZ from ABC::XYZ::myscript from the filename string. Or something to that effect, the ABC::XYZ is taken from your @INC I guess. I also guess that it's likely the eval refers to eval'ing some require'd modules. You could change the code like: [defined($self->profile) ? $self->profile->inc : () ], that is, give it an empty @INC if profile is undefined.

However, something must be seriously wrong in your usage and right now you are the only one who can fix that, the rest of us we are just guessing wildly. So, reduce this problem to a minimum. Also, show the versions of all modules involved.