A day ago, a month ago (time no longer has real meaning anymore), I was ask to look into moving our code away from SVN (Subversion) [1] and into git [2]. Ever since I've been pretty much busy with the shaving of yaks [3]—lots and lots of yaks.
And it's more than just converting a repository of code from SVN to git—it's also breaking up what is basically a monorepos [4] into lots of separate repos for reasons (operations hates having to checkout the 800 pound gorilla for the 4 oz. banana). And without losing history if at all possible.
Lots of yaks to shave in this project.
So I've been learning about submodules in git and while I like git, I'm not a fan of the submodule. First, when you clone a repository with submodules (git clone https://git.example.com/foo.git) you don't get the submodules. That's another two steps to get them (git submodule init; git submodule update). I solved that issue with a new Makefile target:
getmod:
git submodule init
git submodule update
And on the build system, I made sure that make getmod was done prior to make. That issue solved.
Another issue—we use Lua [5] in our department, but we ended up with using two different versions. The stuff I built is still using 5.1.5, while a new project a fellow cow-orker wrote used 5.3.2. This is a chance to consolidate some dependencies, and to that end, I have a new single Lua repo with every version of Lua from 5.1.4 to 5.3.5 (with all the patches [6] applied). But as I found out (and many yaks were shaved to bring me this information) you can't just checkout a particular tag or branch for a submodule.
Grrrrrr.
So I solved that issue in the Makefile as well:
VLUA := $(shell cd deps/lua ; git describe --tag) ifneq ($(VLUA),"5.1.5.p2") DUMMY := $(shell cd deps/lua; git checkout 5.1.5.p2) endif
This checks to see which version of Lua is checked out, and if it's not the one I want, check out the version I do want. I also had to make sure the .gitmodule file had ignore = all set:
[submodule "deps/lua"]
path = deps/lua
url = https://git.example.com/lua.git
ignore = all
to prevent git status from freaking people out.
I figure this will keep me busy for the next few months at least. Or maybe days. Time just flows strangely these days.
[1] https://subversion.apache.org/
[3] http://catb.org/jargon/html/Y/yak-shaving.html
[4] https://en.wikipedia.org/wiki/Monorepo