A bit more discussion on $PYTHONBREAKPOINTHOOK

pep-0553.rst

@@ -90,6 +90,7 @@ We want to get confirmation from at least one alternative debugger
 implementation (e.g. PyCharm) that the hooks provided in this PEP will
 be useful to them.
 
+
 Breakpoint bytecode
 -------------------
 
@@ -102,6 +103,7 @@ bytecode streams to trampoline into their own debugger.  Having a
 in order to invoke this trampoline.  *NOTE*: It probably makes sense to split
 this idea into a separate PEP.
 
+
 Environment variable
 --------------------
 
@@ -114,6 +116,20 @@ This would provide execution environments such as IDEs which run Python code
 inside them, to set an internal breakpoint hook before any Python code
 executes.
 
+If we did add that hook, what should be the default value and should
+it be easy to disable ``breakpoint()``?  The rationale here is calls
+to ``breakpoint()`` that might accidentally sneak into production.
+
+The author's opinion is that if we support this environment variable
+it should be enabled --and point to ``pdb.set_trace()``-- by default.
+This way it Just Works for the average developer.  The maintainers of
+CI, build, or production systems should be able to easily configure
+their environments to disable ``breakpoint()``.  We probably want to
+support a shorthand for "disable built-in breakpoint()", e.g.::
+
+    $ export PYTHONBREAKPOINTHOOK=0
+
+
 Call a fancier object by default
 --------------------------------