The following change to samba breaks building lib/crypto/md5.*  on OpenBSD as it pulls in the /usr/include/m5.h file.

diff -u -r --new-file --exclude .svn --exclude CVS samba-3.6.6//lib/crypto/md5.h samba-3.6.7//lib/crypto/md5.h
--- samba-3.6.6//lib/crypto/md5.h	2012-06-24 19:21:16.000000000 +0200
+++ samba-3.6.7//lib/crypto/md5.h	2012-07-30 19:13:16.000000000 +0200
@@ -5,15 +5,27 @@
 #define HEADER_MD5_H 
 #endif
 
+#ifdef HAVE_MD5_H
+/*
+ * Try to avoid clashes with Solaris MD5 implementation.
+ * ...where almost all implementations follows:
+ * "Schneier's Cryptography Classics Library"
+ */
+#include <md5.h>
+#else
+
 struct MD5Context {
 	uint32_t buf[4];
 	uint32_t bits[2];
 	uint8_t in[64];
 };
+typedef struct MD5Context MD5_CTX;
 
 void MD5Init(struct MD5Context *context);
 void MD5Update(struct MD5Context *context, const uint8_t *buf,
 	       size_t len);
 void MD5Final(uint8_t digest[16], struct MD5Context *context);
 
+#endif /* !HAVE_MD5_H */
+
 #endif /* !MD5_H */


cc -O2 -pipe -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS -I. -I/usr/ports/pobj/samba-3.6.7/samba-3.6.7/source3 -I/usr/ports/pobj/samba-3.6.7/samba-3.6.7/source3/../lib/iniparser/src -Iinclude -I./include  -I. -I. -I./../lib/replace -I./../lib/tevent -I./librpc -I./.. -DHAVE_CONFIG_H  -I/usr/local/include -Iinclude -I./include -I. -I. -I./../lib/replace -I./../lib/tevent -I./librpc -I./.. -I./../lib/popt  -I/usr/ports/pobj/samba-3.6.7/samba-3.6.7/source3/lib -I.. -D_SAMBA_BUILD_=3 -D_SAMBA_BUILD_=3 -fPIC -c ../lib/crypto/md5.c -o ../lib/crypto/md5.o
../lib/crypto/md5.c:26: error: conflicting types for 'MD5Transform'
/usr/include/md5.h:39: error: previous declaration of 'MD5Transform' was here
../lib/crypto/md5.c: In function 'MD5Init':
../lib/crypto/md5.c:48: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:49: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:50: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:51: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:53: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:54: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c: In function 'MD5Update':
../lib/crypto/md5.c:67: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:68: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:69: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:70: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:77: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:85: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:86: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:86: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:93: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:94: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:95: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:95: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:102: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c: In function 'MD5Final':
../lib/crypto/md5.c:115: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:119: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:129: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:130: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:130: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:133: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:138: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:141: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:141: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:142: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:142: error: 'struct MD5Context' has no member named 'bits'
../lib/crypto/md5.c:144: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:144: error: 'struct MD5Context' has no member named 'in'
../lib/crypto/md5.c:145: error: 'struct MD5Context' has no member named 'buf'
../lib/crypto/md5.c:146: error: 'struct MD5Context' has no member named 'buf'
gmake: *** [../lib/crypto/md5.o] Error 1
*** Error code 2

Stop in /usr/mystuff/net/samba (line 2496 of /usr/ports/infrastructure/mk/bsd.port.mk).
*** Error code 1