[Python-Dev] A "new" kind of leak

Michael Hudson mwh@python.net
13 Apr 2002 11:12:23 +0100

Tim Peters <tim.one@comcast.net> writes:

> I think it took about 4x longer than it would have *just* to fix it
> in the head.  This surprised me.  In retrospect, though, it doesn't:
> obviously, there's twice as much of everything (twice as many
> checkins to do, twice as many files to edit, twice as many tests to
> run, etc), and there's no "economy of scale".  But it's worse than
> just that, because there are endless little costs switching between
> them, and especially on Windows where I use a GUI to build (and have
> to poke around finding the right project file to load), and changing
> directories in a DOS box is clumsy, and I also wanted an additional
> Cygwin shell to try to apply a patch, generated on the trunk, to the
> 2.2 branch.  Trying to switch among all these things while the
> time-consuming parts are running, in different parts of the process
> on different branches, quickly leads to mistakes, and then there's
> extra time to recover from those.  There's also an urge to try to
> copy collateral text (checkin notes, NEWS) from one branch to the
> other, and so more little files get created to effect the transfer.
> So it goes -- I didn't think we'd get twice the fixes for free
> <wink>.  This was a small bugfix, and so the overheads swamped the
> time spent just fixing the code.  For a larger bugfix I'd expect
> more like a factor of 3 oerall -- unless the code can't be
> backported mechanically, in which case it may take arbitrarily
> longer.

For patches that 

cvs up -j blah -j blat file

can handle, I have a setup that make porting them the work of seconds.
It takes a little while to set up, so I batch them.

I don't run the tests for every checkin this way so I guess I risk
pain -- if I plough through 20 or so fixes in a run and find
somethings broken, working out what did it could be entertaining.
Hasn't happened yet, though.

What I'm saying is, if getting fixes into the tree is awkward for you,
don't worry about it /too/ much.

I want to fiddle my scripts a bit, but they should appear in Tools/ at
some point...


  Strangely enough  I saw just such a beast at  the grocery store
  last night. Starbucks sells Javachip. (It's ice cream, but that
  shouldn't be an obstacle for the Java marketing people.)
                                         -- Jeremy Hylton, 29 Apr 1997