The use attributes line is there for two reasons:
  1. Loads attributes.pm if it isn't loaded.
  2. Regardless of if it was loaded, calls attributes->import( ... ) with the params passed.

I'm willing to bet that what happens is that the breakpoint is set on the "sub a", but that function isn't executed. Instead, it is replaced by the one declared by attributes. Unfortunately, the attributes heavy lifting code is within the Perl source, so it's a little less accessible to one such as I.

My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

In reply to Re^2: bug in the debugger? breakpoints in subroutines ignored if attributes present by dragonchild
in thread bug in the debugger? breakpoints in subroutines ignored if attributes present by wu-lee

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