I want to store a project in Mercurial that contains external code (which can be modified by me) coming from Git and SVN repositories. In SVN I would solve this with vendor branches and copy the code around, but I understood that in Mercurial it's better to have different repositories for different projects, and pull between them when needed.
The project layout will be like this:
- externalLibraryA [comes from a SVN repo] - ...with some extra files from me - externalLibraryB [comes from a SVN repo] - ...with some extra files from me - externalPluginForExternalLibraryB [comes from a Git repo]
In Subversion I would create vendor
dir and a trunk
dir, copy all external libraries first in vendor
, and then in the right place in trunk
. (I think) I can do this in Mercurial too, with subrepositories, but is this the best way to do this?
I tried setting up different repositories for the external libraries, but then it seems I can't pull the externalLibraryARepo
into the externalLibraryA
directory of my main repository? It goes in the main directory, which is not what I want. I can also create a Mercurial mirror repository and include it as a subrepo in my main repository, but then the changes in this subdirectory go to the mirror repository, while I want them to stay in the main repository.
It depends on whether your vendor code is going to be customized by your team or not. Our teams have had a great deal of success maintaining a named "vendor" branch on repositories with our own customizations on branches named by project name. This vendor code is then easily included in a project as a subrepository.
A caveat to this approach: if active development is going on in the subrepository, best keep it to directly editing the subrepository as a separate clone, otherwise it becomes necessary to pay close attention to the top-level repository so you don't inadvertantly bump your .hgsubstate forward to the wrong revision and break your build.
Watch out for merges of the top-level repository (your project) between versions which point to different named branches of your subrepository, as this can result in a merge between the "vendor" and "project" branches in the subrepository as it recurses, which may not be desirable.
Note that this functionality may change in the future as well, as some "warm" discussions have been taking place in recent months on the mercurial-devel mailing lists about the future of subrepository recursion.
edit: I just saw this discussion in the related links as well, which seems relevant: https://stackoverflow.com/a/3998791/1186771