Switch / Checkout Branch ist not working - libgit2

Question

I'm using Version 0.19
I've a remote branch named 'dev'
after cloning i want to switch to this branch.
i found some code which performs an update to the branch. but for me it doesn't work.
I also try to run a checkout after this which also doesnt work.
When viewing the git log after the code i see the changesets of the master branch. But the local branch name is the name of the given name for the created branch (e.G. "dev")
what am i doing wrong?
private static Branch SwitchBranch(Repository repo, RepositoryProperties properties)
{
string branchname = properties.Branch;
Branch result = null;
if (!string.IsNullOrWhiteSpace(properties.Branch))
{
Branch remote = null;
foreach (var branch in repo.Branches)
{
if (string.Equals(branch.Name, "origin/" + branchname))
{
remote = branch;
break;
}
}
string localBranchName = properties.Branch;
Branch localbranch = repo.CreateBranch(localBranchName);
Branch updatedBranch = repo.Branches.Update(localbranch,
b =>
{
b.TrackedBranch = remote.CanonicalName;
});
repo.Checkout(updatedBranch);
result = updatedBranch;
}
return result;
}

Answer 1

The xml documentation of the CreateBranch() overload you're using states "Creates a branch with the specified name. This branch will point at the commit pointed at by Repository.Head".
From your question, it looks like you'd like this branch to also point to the same Commit than the remote tracking one.
As such, I'd suggest you to change your code as follows:
Branch localbranch = repo.CreateBranch(localBranchName, remote.Tip);

Answer 2

Be aware that you can only create the local branch once. So you're going to get an error the second time. At least, I did.
Branch localbranch = repo.Branches.FirstOrDefault(x => !x.IsRemote && x.FriendlyName.Equals(localBranchName));
if (localbranch == null)
{
localbranch = repo.CreateBranch(localBranchName, remote.Tip);
}
Branch updatedBranch = repo.Branches.Update(localbranch,
b =>
{
b.TrackedBranch = remote.CanonicalName;
});
repo.Checkout(updatedBranch);