Re: tar ball vs. git development questions

Jim Abernathy

On 01/22/2012 08:12 PM, Gary Thomas wrote:
On 2012-01-22 13:19, James Abernathy wrote:
I have used both git and the tarball methods of bitbaking projects, all of them derivatives of the examples in the Yocto documentation. I was having issues using the local clone of
the Yocto kernel git repository this weekend. I had successfully done that before, but I was rebuilding the PC workstation, and getting everything setup and tested some of the
meta-intel BSPs to make sure I had everything right. Cloning the linux-yocto-3.0 repository was successful, but the bakes against it failed. I made sure I had poky-extras setup
right, but I still had problems. To isolate the problem, I changed to building with the tarballs and everything worked fine.

So that got me thinking what are the differences between the 2 methods:

* I assume that if I use the tarball method, bitbake, using the recipes, pulls down files from the online repositories and puts those files into the centralized local download
directory ($DL_DIR), allowing reuse instead of re-downloading each time. The content downloaded for linux-yocto-3.0 is exactly what would be pulled from the local repository if
I used a local clone of the git repository for linux-yocto-3.0.
* If my assumption above is correct, if I'm not modifying the source code of the kernel (only changing config parameters), then once you've run at least one build with the
tarball method, the $DL_DIR directory contains all the files you'll need to build any image with linux-yocto-3.0. So there is no need to have a local clone of the kernel
repository for speeding up development. Am I right?
* If I have a successful creation of a bare clone of linux-yocto-3.0.git, how could builds of Edison packages be failing? That makes me concerned about using git and successfully
repeating builds of stable branches like Edison.
If you set BB_GENERATE_MIRROR_TARBALLS = "1" (e.g. in local.conf)
then you'll get tarballs which hold the git repositories after
download. You can then reuse these (by sharing the DL_DIR or
using a local mirror). Does that help with the issue you're seeing?
I'm not sure it does. I don't want poky to do more work. I have my download directory, $DL_DIR, outside my build directory so I can keep it run to run, as mentioned in the comments in local.conf. I was trying to understand 2 basic questions:

1. what could be causing build failures using a freshly created bare clone yesterday vs. using the poky-edison-6.0 tarball. It would be scary if you could clone the linux-yocto-3.0 successfully one day and have it be used in a build successfully, but clone it another day and it not work. I figured that bitbake/poky pulled the same information into DL_DIR regardless of whether you pulled from the bare clone locally or straight from the on-line repository.
2. I was trying to look at items to speed up build runs. I thought that if the downloads in DL_DIR were reused if they existed, it would speed up a run. It seems to. So the question is, after the first build, the files I need for linux-yocto-3.0 are in DL_DIR regardless of whether they came from the online repository or the local bare clone. right?

Jim A

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