Cannot checkout Boost from subrepo

[Yzrsah]

According to the Boost Getting-Started document, we should setup Boost by doing this:

git clone --recursive https://github.com/boostorg/boost
cd boost
git checkout boost-1.68.0
./bootstrap.sh
./b2 headers

When attempting to do so:

git subrepo clone https://github.com/boostorg/boost
cd boost
git checkout boost-1.68.0
error: pathspec 'boost-1.68.0' did not match any file(s) known to git.

How can this be resolved?

[grimmySwe]

You should use git subrepo clone -b boost-1.68.0 https://github.com/boostorg/boost to connect your local subrepo to the upstream branch. If you want to update it later, you can just git subrepo clone -f -b boost-1.69.0 https://github.com/boostorg/boost

[Yzrsah]

Could it be possible to have a new command that makes this easier, or more expressive?
The default "git checkout branch" kinda has the simplicity.
-f -b is easy enough, but it is a bit "syntatic"

[grimmySwe]

@zyrsha there is a difference that the regular checkout doesn't update anything in the repo, it just changes the working copy. For git-subrepo case, switching branch will actually create a new commit in your parent directory.

[grimmySwe]

There is some discussion in #336 regarding the checkout, so if you got this issue working, we can track the checkout there.

[Yzrsah]

After cloning a Boost branch with subrepo, it fails to bootstrap and all the sources are missing.
This is due to the submodules not checking out.
The regular method suggested by Boost uses "clone -r" for recursive, or "git submodule update --init"
But subrepo has no such option for updating all submodules or recursive clone.
What is the best way to do this with subrepo?

[grimmySwe]

There are a lot of issues on using submodules with subrepo (#262), our main approach right now is that if you want to use submodules or subrepos, you are best of using the in the entire structure. git-subrepo tries hard to be transparent but that causes problem with submodules as they want to know where in the structure they are.

[Yzrsah]

I see. This makes a genuine concern for Boost. That one is actually rare, it has to do with their efforts to modularize Boost in order to reduce the heaviness of the library dependency. Perhaps the issue can be kept open in case any solutions can be found in the future.

[grimmySwe]

As a workaround you could download Boost as a binary and unpack it as a part of your build steps. Unless of course you plan to actually change things inside Boost.