On 10 May 2018 at 14:43, Ævar Arnfjörð Bjarmason [off-list ref] wrote:

The SHA1 prefix 06fa currently matches no blobs in git.git. When
disambiguating short SHA1s we've been quietly ignoring the user's type
selector as a fallback mechanism, this was intentionally added in
1ffa26c461 ("get_short_sha1: list ambiguous objects on error",
2016-09-26).

I think that behavior makes sense, it's not very useful to just show
nothing because a preference has been expressed via core.disambiguate,
but it's bad that we're quietly doing this. The user might thing that
we just didn't understand what e.g 06fa^{blob} meant.

Now we'll instead print a warning if no objects of the requested type
were found:

    $ git rev-parse 06fa^{blob}
    error: short SHA1 06fa is ambiguous
    hint: The candidates are:
    [... no blobs listed ...]
    warning: Your hint (via core.disambiguate or peel syntax) was ignored, we fell
    back to showing all object types since no object of the requested type
    matched the provide short SHA1 06fa

s/ignored, we/ignored. We/? IMHO, it would read easier.

s/provide short/provided short/

Also: s/SHA1/object id/? That said, you add the warning. The error
message is already there and you are simply following its "SHA1".

Martin