[Python-Dev] Support for the Haiku OS

[Mark Dickinson]

On Sun, Jan 18, 2009 at 11:03 PM, scott mc <scottmc2 at gmail.com> wrote:
> I built 2.7 on Haiku, but am getting failures in the regression tests.
>  Many of them are in math related tests, failing in the 15th decimal
> place on test_decimal and a few others like that, I posted a ticket on
> Haiku's trac for that as it might be related to Haiku's built in math
> lib? (libm is built into Haiku's libroot.so)
> http://dev.haiku-os.org/ticket/3308

Most of these look like libm/libc precision problems to me,
of varying severity.  Some particular comments:

 - the test_float result is worrying: there are a good few places
   where Python depends on eval(repr(.)) round-tripping for
   floats, and it looks as though either the eval or the repr
   is losing significant accuracy.  Actually, there's so much
   accuracy loss that I wonder whether something's being
   cast from double precision to single precision at some
   point.

- test_decimal failing was a bit of a surprise until I saw
  which test was failing:  the decimal module quite
  deliberately does all computation using integer
  arithmetic, and avoids floating-point like the plague,
  so it should be ultra-portable.  Except, of course, the
  recently added from_float method, which converts
  from floats to decimals.  So fix up the floating-point
  and test_decimal should pass again.

- I don't understand where the test_marshall and
  test_random failures are coming from.  These
  could be Python problems (though I think it's
  more likely that they're Haiku floating-point
  problems).  I'd be interested to see short
  code-snippets that reproduce these issues.

- I wouldn't worry so much about the test_math
  and test_cmath failures until you get the others
  sorted out;  the tests are probably stricter than
  they need to be.

Mark