evaluate git-subrepo

howto/puppet.md

@@ -1798,7 +1798,31 @@ twice as well.
 
 ### subrepo
 
-TODO. https://github.com/ingydotnet/git-subrepo
+The [git-subrepo](https://github.com/ingydotnet/git-subrepo) is "an improvement from `git-submodule` and
+`git-subtree`". It is a mix between a monorepo and a submodule system,
+with modules being stored in a `.gitrepo` file. It is somewhat less
+well known than the other alternatives, presumably because it's newer?
+
+It is entirely written in `bash`, which I find somewhat scary. It is
+[not packaged in Debian yet](http://bugs.debian.org/911397) but might be soon.
+
+It works around the "double-commit issue" by having a special `git
+subrepo commit` command that "does the right thing". That, in general,
+is its major flaw: it reproduces many git commands like `init`,
+`push`, `pull` as subcommands, so you need to remember which command
+to run. To quote the (rather terse) manual:
+
+> All the subrepo commands use names of actual Git commands and try to
+> do operations that are similar to their Git counterparts. They also
+> attempt to give similar output in an attempt to make the subrepo
+> usage intuitive to experienced Git users.
+>
+> Please note that the commands are not exact equivalents, and do not
+> take all the same arguments
+
+Still, its feature set is impressive and could be the perfect mix
+between the "submodules" and "subtree" approach of still keeping a
+monorepo while avoiding the double-commit issue.
 
 ### myrepos
 
@@ -1820,14 +1844,14 @@ specific remotes in subdirectories of the monorepo automatically.
 
 ### Summary table
 
-| Approach   | Pros                       | Cons                                     | Summary                   |
-|------------|----------------------------|------------------------------------------|---------------------------|
-| Monorepo   | Simple                     | Double-commit                            | Status quo                |
-| Submodules | Well-known                 | Hard to use, double-commit               | Not great                 |
-| Librarian  | Dep resolution client-side | Unmaintained, bad integration with git   | Not sufficient on its own |
-| r10k       | Standard                   | Hard to deploy, opiniated                | To evaluate further       |
-| Subtree    | "best of both worlds"      | Still get double-commit, rebase problems | Not sure it's worth it |
-| Subrepo    | ? | ? | ? |
+| Approach   | Pros                       | Cons                                     | Summary                           |
+|------------|----------------------------|------------------------------------------|-----------------------------------|
+| Monorepo   | Simple                     | Double-commit                            | Status quo                        |
+| Submodules | Well-known                 | Hard to use, double-commit               | Not great                         |
+| Librarian  | Dep resolution client-side | Unmaintained, bad integration with git   | Not sufficient on its own         |
+| r10k       | Standard                   | Hard to deploy, opiniated                | To evaluate further               |
+| Subtree    | "best of both worlds"      | Still get double-commit, rebase problems | Not sure it's worth it            |
+| Subrepo    | subtree + optional         | Unusual, new commands to learn           | To evaluate further               |
 | myrepos    | Flexible                   | Esoteric                                 | might be useful with our monorepo |
 
 ### Best practices survey