cross release mergemaster question

hi all,
	is there some magic to run mergemaster on a 6.2 host
for a 7.0 distro? 

	mergemaster -m /r+d/7.0/src -d /d/7
fails when trying to compile(why?)

/lib/libcrypt/crypt-md5.c
cc -O2 -fno-strict-aliasing -pipe  -I/r+d/7.0/src/lib/libcrypt/../libmd 
-I/r+d/7
.0/src/lib/libcrypt/../libutil -I/r+d/7.0/src/lib/libcrypt -DHAS_DES 
-DHAS_BLOWF
ISH -Dauth_getval=__auth_getval -Dproperty_find=__property_find 
-Dproperties_rea
d=__properties_read -Dproperties_free=__properties_free -DMD4Init=__MD4Init 
-DMD
4Final=__MD4Final -DMD4Update=__MD4Update -DMD4Pad=__MD4Pad 
-DMD5Init=__MD5Init
-DMD5Final=__MD5Final -DMD5Update=__MD5Update -DMD5Pad=__MD5Pad  -c 
/r+d/7.0/src
/lib/libcrypt/../libmd/md5c.c
/r+d/7.0/src/lib/libcrypt/../libmd/md5c.c: In function `__MD5Update':
/r+d/7.0/src/lib/libcrypt/../libmd/md5c.c:154: error: argument "in" doesn't 
matc
h prototype
/usr/include/sys/md5.h:46: error: prototype declaration
*** Error code 1

thanks,
	danny