This is the same bug as #3966, and is still present in PHP 4.0.1pl2.

I discovered the solution some time ago, but for some reason was unable
to edit my previous bug report.  I was prompted to submit this when I received 
e-mail notification that #3966 had been closed, but no action had been taken.

The problem only occurs with certain (older) Apache versions, though I don't know
which MODULE_MAGIC_NUMBER translates to which apache version.

Output from make:
----
mod_php4.c: In function `php_apache_log_message':
mod_php4.c:282: `requset_rec' undeclared (first use this function)
mod_php4.c:282: (Each undeclared identifier is reported only once
mod_php4.c:282: for each function it appears in.)
mod_php4.c:282: parse error before `)'
make[3]: *** [mod_php4.lo] Error 1
make[3]: Leaving directory `/usr/src/redhat/BUILD/php-4.0.1pl2/sapi/apache'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/usr/src/redhat/BUILD/php-4.0.1pl2/sapi/apache'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/src/redhat/BUILD/php-4.0.1pl2/sapi'
make: *** [all-recursive] Error 1

The problem is due to a simple typo -- it should be "request_rec" rather than
"requset_rec".

Here's a patch for ~phpsrc/sapi/apache/mod_php4.c:

---- BEGIN mod_php4.c.patch ----
--- mod_php4.orig	Mon Jul 31 08:35:32 2000
+++ mod_php4.c	Mon Jul 31 08:58:24 2000
@@ -284,7 +284,7 @@
 #if MODULE_MAGIC_NUMBER >= 19970831
 		aplog_error(NULL, 0, APLOG_ERR | APLOG_NOERRNO, ((request_rec *) SG(server_context))->server, "%s", message);
 #else
-		log_error(message, ((requset_rec *) SG(server_context))->server);
+		log_error(message, ((request_rec *) SG(server_context))->server);
 #endif
 	} else {
 		fprintf(stderr, message);
---- END ----