apache 1.3.0
php 3.0
SunOS 4.1.4 (w/ libraries that come with the system)
gcc-2.7.2.2

On SunOS 4, a system without strerror in its provided libraries, both
apache-1.3.0 and php-3.0 supply a replacement function named strerror.
At link time for httpd, ld complains about a multiple definition and
aborts.

I won't venture to say if it is an apache or a php problem.  It's rather
a question of convention and synchronisation between the two projects.
(I made a similar report to the other project, apache PR#2548.)

I use php as a static module.  (There are problems more complicated to
solve on SunOS in trying to use it as a shared module; for instance,
the absence of a shared version of libm.  So static is the simpler way
to go.)

There are three possible ways this could be fixed:

. one or both projects define their replacement function with a prefix
  that is exclusive to them (duplication, but a small one)

. apache configuration detects that php3 is used as a static module
  and provides its own strerr, and so apache does not define
  NEED_STRERR, even when strerror is not provided by the os

. similarly, php does not provide a strerror if it detects that apache
  will provide one

Of course, care should be taken with the last two options that we
don't end up with no strerror at all.