QuickCheck failures with new 'tar' release...

[Michael Alan Dorman]

I'm not sure if there's a more appropriate venue to bring this up; the
package doesn't seem to have any sort of explicit issue tracker.

On the NixOS build servers, we're seeing across-the-board failures for
the 0.4.2.0 release of the 'tar' library, specifically, two properties
that were added in the latest release.

It looks to me like prop_lookup is fundamentally broken---it falls over
in the face of a lookup for 'a/b' in a list of entries that includes
'a/b/c/d', because while the library lookup function returns a match
including the remainder of the path as a result, the Data.List.lookup
that it's comparing against returns nothing.

I don't see a way for the test as it is constituted to work reliably.
I'm going to guess that prop_valid suffers from a similar issue.

Either way, it would be nice if they could either be corrected, or diked
out until that happens.

Mike.