Jukka Salmi <j+nbsd@2007.salmi.ch> wrote:

> Some debugging revealed that errno changes while pthread_create(3) is
> called even though that call returns success (0).

As Greg Toxel suggested, this is allowed.

Per "The Open Group Base Specifications Issue 6" a.k.a. "IEEE Std
1003.1, 2004 Edition" (I can never keep track of the POSIX standard
naming, but it's POSIX):

   "The setting of errno after a successful call to a function is
   unspecified unless the description of that function specifies that
   errno shall not be modified."

The same standard makes no mention of errno when describing
pthread_create(), for either successful or unsuccessful returns from
that function.

Regards,

Giles