This is the error message:

making all in find
cc -c -DHAVE_CONFIG_H -I.. -I../lib -I/usr/pkg/include -O2 -I/usr/pkg/include find.c
find.c: In function `main':
find.c:138: warning: return type of `main' is not `int'
cc -c -DHAVE_CONFIG_H -I.. -I../lib -I/usr/pkg/include -O2 -I/usr/pkg/include fstype.c
cc -c -DHAVE_CONFIG_H -I.. -I../lib -I/usr/pkg/include -O2 -I/usr/pkg/include parser.c
parser.c:66: error: conflicting types for `endgrent'
/usr/qnx632/target/qnx6/usr/include/grp.h:53: error: previous declaration of `endgrent'
parser.c:67: error: conflicting types for `endpwent'
/usr/qnx632/target/qnx6/usr/include/pwd.h:59: error: previous declaration of `endpwent'
cc: /usr/qnx632/host/qnx6/x86/usr/lib/gcc-lib/i386-pc-nto-qnx6.3.0/3.3.5/cc1 error 1
*** Error code 1

Stop.
bmake: stopped in /usr/src/HEAD/pkgsrc/sysutils/findutils/work/findutils-4.1/find


The fix is to define _POSIX_SOURCE. Patch generated with svn diff is attached.