The manifest-SHA.txt produced by the Bag export is not compatible with command-line shasum. When I try to validate the files in the manifest with shasum, I get the following error:
$ shasum -c manifest-SHA1.txt
shasum: manifest-SHA1.txt: no properly formatted SHA1 checksum lines found
The BagIt spec for manifest files may not be compatible with shasum, but if it is, then we should make them compatible for ease of validation.