Intended audience: software engineers working with Git who happen to come across this value and want to confirm that it has particular significance.
e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 is used by Git to indicate an empty blob (an empty file).
To verify this, we can construct the object content manually and hash it. The format for object contents is
<type> <size>\0<contents> (where
\0 denotes the null byte). In this case, the type is
blob and the size is
0, and there are no contents. We can compute the hash with one of the following commands:
$ printf 'blob 0\0' | shasum e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 - $ printf 'blob 0\0' | openssl dgst -sha1 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
See also Why does Git hash only the Contents of A File? for some related discussion.