[Pkg-haskell-maintainers] Bug#658661: haskell-unix-bytestring: FTBFS on i386: Could not deduce (Eq a)

[Aaron M. Ucko]

Source: haskell-unix-bytestring
Version: 0.3.5-1
Severity: serious
Justification: fails to build from source

The build of haskell-unix-bytestring on i386 (but not, for some
reason, any other architectures) failed:

src/Foreign/C/Error/Safe.hs:103:41:
    Could not deduce (Eq a) arising from a use of `=='
    from the context (Num a)
      bound by the type signature for
                 eitherErrnoIfMinus1 :: Num a => IO a -> IO (Either
		 C.Errno a)
      at src/Foreign/C/Error/Safe.hs:103:1-43
    Possible fix:
      add (Eq a) to the context of
        the type signature for
          eitherErrnoIfMinus1 :: Num a => IO a -> IO (Either C.Errno
	  a)
    In the first argument of `eitherErrnoIf', namely `(- 1 ==)'
    In the expression: eitherErrnoIf (- 1 ==)
    In an equation for `eitherErrnoIfMinus1':
        eitherErrnoIfMinus1 = eitherErrnoIf (- 1 ==)

(There were also similar errors concerning eitherErrNoIfMinus1Retry
and eitherErrNoIfMinus1RetryMayBlock, on lines 106 and 111
respectively.)

You can find the full log at
https://buildd.debian.org/status/fetch.php?pkg=haskell-unix-bytestring&arch=i386&ver=0.3.5-1&stamp=1328365694

Could you please take a look?

Thanks!