GitCommitHash
GitCommitHash[directory]⟹hash
returns the SHA1 hash for the HEAD of the git repository given by directory.
GitCommitHash[directory]⟹$Failed
returns $Failed if the given directory is not a valid directory (or git repository).
GitCommitHash[directory]⟹hash
returns the SHA1 hash for the HEAD of the git repository given by directory.
GitCommitHash[directory]⟹$Failed
returns $Failed if the given directory is not a valid directory (or git repository).