Re[surrecting]: Version Control and Public Repository

[Alexander Kobel]

Dear all,

long time ago there was this thread about version controlling Lily 
scores, and much more recently Urs' excellent essay and tutorial on the 
LilyPond blog [1].

Now, that surely is a great read, but I'm left with one question. Over 
time, I've collected a few scores, made with different LilyPond 
versions, which I want to put into a VCS repo now and clean up a bit. At 
some (early) point though, I started to use include files for common 
tweaks and shortcuts.
So I used, say, my-tweaks-0.1.ly for scoreA, and an extended version 
my-tweaks-0.2.ly later for scoreB. Now I recognize that it feels wrong 
to maintain my-tweaks-* in different files, because it really is a 
development from 0.1; also, it means copy-pasting to a new file whenever 
a nice add-on should be available for new scores. "Where's my most 
recent house style?"
On the other hand, some tweaks introduced in newer versions of the 
include do not work well together with local tweaks of scoreA; hence, I 
want to at least refer to which version of my-tweaks-?.ly I used there 
last time I touched the piece. (E.g., I have scores which predate Joe's 
tremendous improvements to vertical spacing; it's obvious that I have to 
rewrite all spacing code if I convert them to today's Lily, but I need 
the old state of tweaks for everything else.)

I'm pretty sure that's a common problem for repos containing several 
separate projects, unlike source code for a single library or 
application which needs to be updated entirely in one shot when 
dependencies change. So, most probably there's a `proper` way to deal 
with the problem. But, which? Any suggestions?

The only possibility I see to keep the different versions (in git) 
somewhat cleanly separated is to use a house-style branch for the 
includes, and use one branch per project (a.k.a. score). If necessary, 
merge the recent modifications from house-style to project. This sounds 
clean, but also like overkill - after all, I usually write 2-4 
pages-scores (max was around 20 pages, I think), not operas.
On the other hand, I preferably don't want to check every time I modify 
an include whether the change has negative impact on any of my score, 
but I also don't want to be stuck with some broken old project for a 
little modification. (Like, extract choir parts from the piano 
reduction--which typically happens ~1 hour before the rehearsal...)


Thanks in advance,
Alexander


[1] http://lilypondblog.org/2013/09/write-lilypond-code-for-version-control/