Thanks for the quick reply, Mikhail, but no: the output of "cabal sandbox list-sources" looks fine.

Any other ideas, anyone?

--Eric

On Friday, August 14, 2015 2:41 PM, Mikhail Glushenkov wrote:
Hi,

On 14 August 2015 at 21:00, Eric <devnull1999@yahoo.com> wrote:
> I'm getting a warning
>
>> Warning: Could not list sources of the add-source dependency 'xyz'.
>> Skipping the timestamp check.
>
> when building a sandboxed project with add-source dependencies.  I tried
> increasing the verbosity of cabal, but it still won't tell me what's going
> wrong so I can fix it.
>
> Any suggestions on how to debug or fix this?

Check the output of `cabal sandbox list-sources`. A likely cause is
that one of add-source dependencies refers to a non-existent
directory.