source-repository-package branch failure

[georgefst]

With:

source-repository-package
  type: git
  location: git://github.com/georgefst/pretty-simple.git
  branch: experimental

at the top of my cabal.project, I get the failure fatal: '--detach' cannot be used with '-b/-B/--orphan'. Unclear what's causing this. It works fine with master.

git version is 2.7.4, which is pretty old (can't upgrade right now on my work machine), so if that's the issue, I'll just work around it.

[phadej]

An example output

Project settings changed, reconfiguring...
creating /code/public-haskell/tree-diff/dist-newstyle
creating /code/public-haskell/tree-diff/dist-newstyle/cache
/usr/bin/git --version
creating /code/public-haskell/tree-diff/dist-newstyle/src
/usr/bin/git clone --no-checkout 'git://github.com/georgefst/pretty-simple.git' /code/public-haskell/tree-diff/dist-newstyle/src/pretty-si_-3997a25a56f97597
Cloning into '/code/public-haskell/tree-diff/dist-newstyle/src/pretty-si_-3997a25a56f97597'...
remote: Enumerating objects: 55, done.
remote: Counting objects: 100% (55/55), done.
remote: Compressing objects: 100% (39/39), done.
remote: Total 1204 (delta 16), reused 44 (delta 11), pack-reused 1149
Receiving objects: 100% (1204/1204), 288.14 KiB | 1.56 MiB/s, done.
Resolving deltas: 100% (514/514), done.
/usr/bin/git checkout --detach --force experimental --
fatal: '--detach' cannot be used with '-b/-B/--orphan'

and looks like we have an unsolved TODO

cabal/cabal-install/Distribution/Client/VCS.hs

Lines 628 to 629 in 5ce6b08

	checkoutArgs = "checkout" : ["--force", checkoutTarget, "--" ]
	checkoutTarget = fromMaybe "HEAD" (srpBranch `mplus` srpTag) -- TODO: this is definitely wrong.

[elldritch]

For anyone else who arrives at this, you can work around it by cding into the cloned directory in dist-newstyle and manually running the correct git checkout yourself.

[georgefst]

After all this time, I have suddenly accidentally discovered that branch is optional, and if you're specifying tag anyway, fairly pointless. Now that I think about it, it would be weird if this wasn't the case.

Admittedly, now that I look, the documentation clearly states:

This field is optional.

So this issue isn't quite as high priority as I'd thought. Would still be nice though!

[liskin]

@georgefst What if you aren't specifying tag:, though?

[georgefst]

@georgefst What if you aren't specifying tag:, though?

Well, then, as it stands, you can't use branch. I'm not arguing that this issue should be closed. I'm just pointing out for anyone who comes across this that it isn't a show-stopper in many cases.

[liskin]

I see, thanks for the clarification. (I got confused because the example at the top of this issue uses a branch, not a tag, and it's exactly the usecase I'm concerned about.)

[tomjaguarpaw]

I also came across this. On searching for the error fatal: '--detach' cannot be used with '-b/-B/--orphan' I arrived here. To make @georgefst's workaround crystal clear: don't use branch just use tag (which actually means to seem "commit"). For example, in cabal.project:

packages: *

source-repository-package
 type: git
 location: git@github.com:purebred-mua/purebred-email.git
 tag: 19e06063d03c477f33f3add82c1b4f7c6e77b801