How is the phrase "When your program breaks, you get to keep both pieces." commonly used?

Question

One such example in source code files open-sourced by Apple:

/* 
 * WARNING  DANGER  HAZARD  BEWARE  EEK
 * 
 * Everything in this file is for Apple Internal use only.
 * These will change in arbitrary OS updates and in unpredictable ways.
 * When your program breaks, you get to keep both pieces.
 */

The warning basically means the source code is internal to Apple and is subject to change. Software developers who use these files should not expect the 'interface' to stay the same between version. If the interface is indeed changed, any program that depends on the file will be broken.

What I do not quite understand are:

1. Is the phrase When <something> breaks, you get to keep both pieces a common one? If so, how is it usually used?

2. Does 'both pieces' means 'two pieces' here?

3. Is it supposed to be playful in tone? Is there any other implied meaning based on the context?

Answer 1

1. I have read this phrase before. I'd say it's common among programmers who are writing their own warnings or licenses for software.

2. Yes. I believe the metaphor relates to an object that is broken in two, as if software could break in this manner.

3. Yes, it is playful. It's terse and sarcastic: it seems it may be a criticism of the verbosity of legalese in software licenses.

Answer 2

As far as I've been able to determine, the canonical appearance of "if it breaks, you get to keep both pieces" in software development comes from the manual page of the BSD chat program, a tool for communicating with modem hardware. The earliest version of that manual page I could find was from 1994 in the FreeBSD 2.0 distribution:

COPYRIGHT

The chat program is in public domain. This is not the GNU public license. If it breaks then you get to keep both pieces.

The statement was a clear dig at the GNU tools from the Free Software Foundation, which were infamous for having long copyright sections in their manual pages dotted with ALL CAPS warranty disclaimers, for example this is the equivalent section from the man page of GNU make:

COPYRIGHT

Copyright (C) 1992, 1993, 1996, 1999 Free Software Foundation, Inc. This file is part of GNU make. GNU make is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

GNU make is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with GNU make; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

These days, the standard GNU copyright section is much shorter, if it appears at all, but at the time the GNU General Public Licence was legally novel and untested, and the FSF felt it best to be careful.

Since the userland of OS X is based on BSD, it's very likely the term made its way into some Apple developer's vocabulary through that tradition.

Answer 3

It's just another way of saying that we are not responsible of anything, but in a funnier way.

A variation of the sentence above is "you get to keep both halves", as seen in https://launchpad.net/~gnome3-team/+archive/ubuntu/gnome3-staging:

If they break your system, you get to keep both halves.

Answer 4

I'm an open source software developer with many years of experience. This phrase is used a lot in open source, IT, and specifically computer support.

1) Is the phrase "When breaks, you get to keep both pieces" a common one? If so, how is it usually used?

It is a common phrase between professional geeks in IT. It is used to indicate that certain combinations of software/hardware/equipment are incompatible, and may lead to irreversible damage. It is also an indication that one doesn't want to provide support for something that is deemed unstable / unsupportable.

I think the closest non-geeky way to say the same thing would be: "If you go down this path, you are on your own."

Alice: Will all of our company internal software still work for me, if I upgrade to Windows 10? Bob: If it breaks, you'll get to keep both pieces.

2-days later

Alice: I've upgraded to Windows 10, and also upgraded Office, and now any documents I edit cannot be later opened by anybody else on the team with older laptops. I have a deadline, can you fix this?

Bob: No, I told you, if it breaks, you'll get to keep both pieces.

What Bob is trying to say is "I told you so", "go away", "you are on your own", and "it's not my problem". Thus it's a generic excuse. Sometimes it comes across as patronizing, especially when it later turns out that it's a real problem which should have been supported/working, instead it was dismissed by Bob. That would be called a bug denial.

2) Does 'both pieces' means 'two pieces' here?

It means all the pieces that are broken, kind of equivalent of "don't do that" when asking a doctor why it hurts when you do a particular action.

3) Is it supposed to be playful in tone? Is there any other implied meaning based on the context?

Well, it can be used in any tone one likes from nice to angry. The phrase is informal by nature, but it's not a joke. One seriously means it as a caution / warning. This can go on:

Carol: Bob, did anybody upgrade to windows 10 yet?

Bob: Only Alice, and it broke Office for her. But you know, she got to keep both pieces.

Carol: Well, I don't use that. Here be dragons.

Carol heard the warning, accepts responsibility for any fallout, and goes ahead with the upgrade to see what happens (and breaks).