Using GPL-incompatible free library
Suppose that in the code phase I use a library which is under a free-as-in-freedom license which happens to be incompatible with the GPL 3. The way I think it works is as follows.
The LPC requires me to license my submission under the GPL 3. Which I can do as I am the sole author (unless the other license has strange restrictions).
Everybody else can't do much with that submission due to the incompatibility. They could make use of modified versions, though, which cut out the library.
But by dual-licensing my submission, for example (GPL 3 | WTFPL), I can turn it into free software while still obeying the requirements of the LPC. Then people could just chose to receive it under the WTFPL and do whatever the want with it. And as the recipients have all the freedoms meant to be guaranteed by the GPL 3, I am still within the spirit of the rules, not only their letter.
Now, did I get that right?
Your submission, as a whole, won't be "under the GPL 3.0 license" if it uses an incompatible library. It won't even be legally re-distributable.
@Anonymous:
You might want to read this for information about using GPL-incompatible libraries in a GPL program.
@CruzR: Thanks for the link. I was not familiar with version 3 of the GPL.
So you can have a linking exception and pristine GPL 3 at the same time. That solves the problem, of course.
What library are you using? If I knew, I could probably give you an exact answer.
Bart
@bart: It is not about a specific library -- yet.
As the draft rules require me to annouce any used library a week in advance (and the way I am working this means I have to annouce them before I know I need them), I will have to collect a list of libraries that I don't want to rule out I will be using. I have not exactly started yet, I still hope the draft rule will not be a final rule.
Anyway, the only worry I still have after CruzR's post is when the library is under the GPL 2 (without "or later"). But it's probably not much of a constraint to just avoid those few libraries.
You can only use the linking exception if you wrote all the other code yourself.
If your program began life as someone else's GPL stuff, or you use GPL libraries, then you cannot use the linking exception because it is not all your code -- the other people have not given their permission to have a linking exception on their code.
It will be legally distributable -- you can distribute both your code and the library as source code. You just won't be able to distribute a linked binary.
-- hendrik