andriod4sam_v4.0 tag breaks buildroot

[ringlej]

We are building at91bootstrap3 via buildroot using tag v4.0.8:

BR2_TARGET_AT91BOOTSTRAP3=y
BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_GIT=y
BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_REPO_URL="https://github.com/linux4sam/at91bootstrap.git"
BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_REPO_VERSION="v4.0.8"

But the buildroot build fails when it gets to building at91bootstrap when it tries to do git fetch origin -t

nerves@fa8f3906b4a7:/nerves/dl/at91bootstrap3/git$ git fetch origin -t
From https://github.com/linux4sam/at91bootstrap
 ! [rejected]          Android4sam_v4.0 -> Android4sam_v4.0  (would clobber existing tag)
 * [new tag]           android4sam_v4.0 -> android4sam_v4.0

Could one of the above tags please be deleted via git push origin :android4sam_v4.0?

I realize that this is because I'm building on a Mac with a case insensitive APFS filesystem, but if this is the only reason my build fails it would be nice if one of those two tags is deleted so I don't have to mess with creating a new volume just because of this.

Thank you!