Problem

When performing a Git LFS operation, like for example "clone" or "smudge", the operation will throw an "unsupported protocol scheme" error.

Diagnosis

in the build log, or git-lfs log, or command output, the following message will be printed:

Error downloading object: src/test/Bigfile.img (7854894): Smudge error: Error downloading src/test/Bigfile.img (...): batch response: Post /data/bamboo/xml-data/build-dir/_git-repositories-cache/(...).git/info/lfs/objects/batch: unsupported protocol scheme ""

Cause

This is caused by a Git LFS bug in version 2.1.1 described here: https://github.com/git-lfs/git-lfs/issues/2255

Resolution

1. Update the Git LFS client to the latest version.
2. If the problem persists, try one of the workarounds offered in the bug definition:

   1. Providing the username during cloning apparently makes the protocol being recognized (git is the user for all SSH connections on BitBucket):
      git clone git@bitbucket.org:user/project

   2. Providing the protocol itself works as well:
      git clone ssh://bitbucket.org/user/project

   3. Changing the URLs after cloning would also be a work-around