Comment by MetaCosm
12 years ago
I don't understand, so explain it to me like I am a child, I am certain I am missing something basic and the developers on the project aren't as dumb as it seems.
Seriously, it seems so goddamn basic. I am going to walk you through step by step how I would add an external library to my Go project.
#1. Switch to the go project directory #2. Fork for the new feature (adding_mux) #3. Run go get github.com/gorilla/mux #4. Add import "github.com/gorilla/mux" to my code, use mux for great goodness #5. Commit my code (this is commit of ./src which includes two things, the addition of the new github.com/gorilla/mux/* and my code using that new library) #6. Merge #7. Push
At this point, the commit that was just checked in doesn't need a change to its import path, will never break and will work as it was committed FOREVER. git clone FOO; go build BAR -- victory!
If at some point I want to update that library (new cool feature!)
#1. Switch to go project directory #2. Fork for updating library (update_mux) #3. Run go get -u github.com/gorilla/mux #4. Write code using new awesome features #5. Commit my code (again, "my code" in this case is both the update to the mux library, and my new usage of it, again committed together for great goodness!) #6. Merge #7. Push!
I feel like one of us is bat shit insane, and at this point, I am just hoping it isn't me.
EDIT: Another cool side effect of this is you end up with localized hermetic copies of your code with references for posterity to where you got it, bonus points!
EDIT 2: For reference, there are various forks of the source he "released" (abandoned? Sold for 28k? whatever) ... I think you can start looking at the github network from here: https://github.com/runningwild/haunts
So the key part of the update I was referring to was the following:
In short, original developer has the clone of the OpenGL library in their 'src' directory. While working on Haunts his making changes to it and not pulling updates from upstream. All is well, things will always build on his machine because as you say, it won't update unless he does 'go get -u'.
Fast forward to when the community takes over, they clone the Haunts project and attempt to build it. Now they are using the HEAD of the 'github.com/go-gl/opengl/gl' repository, as specified by the imports path and they find that it no longer compiles.
This is where the problem exists.
The simplest way around this problem is to simply fork the OpenGL Go library (like they have), and reference the fork in the import path. That way no matter what happens in the upstream repository, the Haunts project will continue to compile. The original developer could of then just pushed the changes he was making in his local 'src' directory back to the fork and everything would be fine. When they are ready to take updates from upstream, they simply update their fork and then 'go get -u' on all developer machines.
By forking, or maintaining your own copy of library, you get a level of isolation from the upstream developers.
What you are saying is 100% correct, the Go tools automatically give you this when running 'go get', it clones the library into your 'src' directory. What I am saying is that when working in a team/community environment, you need an additional level of isolation (the fork), so that the entire team can be using the exact same version of the library.
I don't think (hope) either of us are, just not thinking on the same track :) I hope what I've written is clear enough that you can see what I was saying.
> In short, original developer has the clone of the OpenGL library in their 'src' directory. While working on Haunts his making changes to it and not pulling updates from upstream. All is well, things will always build on his machine because as you say, it won't update unless he does 'go get -u'.
The important addition is -- he does not check this clone into his OWN source control, so his source control doesn't have a complete hermetic version of the application, it has a "partial" application... or really "application bits".
> Fast forward to when the community takes over, they clone the Haunts project and attempt to build it. Now they are using the HEAD of the 'github.com/go-gl/opengl/gl' repository, as specified by the imports path and they find that it no longer compiles.
If he had checked it into his version control system (you might call it forking, I call it localizing), they would have had the EXACT same version as him and they would not have had to fulfill that dependency on their own. Also, the same import path would continue to work off this local checked in version.
> By forking, or maintaining your own copy of library, you get a level of isolation from the upstream developers.
I thought that maintaining your own local copy of libraries under /src was the norm for go developers, as the value of hermetic checkouts goes hand in hand with some other Go'isms like static built binaries.