Updating my local git workspace I've run into this problem after git pull on master: llc[214]$ git submodule update fatal: reference is not a tree: 38039b3763f4457f913a006ad1621a476f9a721c fatal: reference is not a tree: 76b3d49e648da6dec2070d36a709129d114615ef fatal: reference is not a tree: 7fbe180e8dc1104195e652aa8a5a7cb1cd48e506 fatal: reference is not a tree: 0c0036aaf02b59b8d0dec631aa013627fb839dcd Unable to checkout '38039b3763f4457f913a006ad1621a476f9a721c' in submodule path 'libs/any' Unable to checkout '76b3d49e648da6dec2070d36a709129d114615ef' in submodule path 'libs/circular_buffer' Unable to checkout '7fbe180e8dc1104195e652aa8a5a7cb1cd48e506' in submodule path 'libs/conversion' Unable to checkout '0c0036aaf02b59b8d0dec631aa013627fb839dcd' in submodule path 'libs/variant' I've confirmed for libs/any that the referenced commit is present on github, but it isn't retrieved by "git fetch" in the submodule workspace, suggesting that it's no longer reachable from any head. I'm guessing this might be related to the "hidden ref" part of the "free to delete old branches" discussion, or maybe there just needs to be another submodule update for these modules. Peter