If build in a prefix, define the system as prefix.

mk/prog.mk

@@ -10,14 +10,14 @@ include ${MK}/sys.mk
 # so we should embed it if different
 # This is currently hardcoded for NetBSD which has two dynamic linkers
 # and we need to use the one in /libexec instead of /usr/libexec
-_DYNLINK_SH=		if test -e /libexec/ld.elf_so; then \
+_DYNLINK_SH=		if test "${PREFIX}" = "" && test -e /libexec/ld.elf_so; then \
 				echo "-Wl,-dynamic-linker=/libexec/ld.elf_so"; \
 			else \
 				echo ""; \
 			fi
 _DYNLINK!=		${_DYNLINK_SH}
 LDFLAGS+=		${_DYNLINK}$(shell ${_DYNLINK_SH})
-LDFLAGS+=		-Wl,-rpath=/${LIBNAME} -L/${LIBNAME}
+LDFLAGS+=		-Wl,-rpath=${PREFIX}/${LIBNAME} -L${PREFIX}/${LIBNAME}
 LDFLAGS+=		${PROGLDFLAGS}
 
 all: depend ${PROG}

src/librc/librc.c

@@ -186,6 +186,10 @@ static bool file_regex (const char *file, const char *regex)
 
 const char *rc_sys (void)
 {
+#ifdef PREFIX
+	return (RC_SYS_PREFIX);
+#else	
+
 #ifdef __FreeBSD__
 	int jailed = 0;
 	size_t len = sizeof (jailed);
@@ -208,6 +212,7 @@ const char *rc_sys (void)
 #endif
 
 	return (NULL);
+#endif /* PREFIX */
 }
 
 static const char *rc_parse_service_state (rc_service_state_t state)

src/librc/rc.h

@@ -232,6 +232,7 @@ bool rc_service_daemons_crashed (const char *service);
  * OpenRC can support some special sub system types, normally virtualization.
  * Some services cannot work in these systems, or we do something else. */
 #define RC_SYS_JAIL    "JAIL"
+#define RC_SYS_PREFIX  "PREFIX"
 #define RC_SYS_UML     "UML"
 #define RC_SYS_VPS     "VPS"
 #define RC_SYS_XEN0    "XEN0"