sem_open(), -lrt and creating a library

I am on HP-UX delta B.11.11

I am using sem_open() and compiling/linking the library by specifying -lrt.

Then, I am creating library like below:

ar cr $libdir/liboscfe.a `cat fe.libs.$$ com.libs.$$`
ranlib $libdir/liboscfe.a

Now, I am compiling another utility sch2db which requires this library liboscfe.a as below:

aCC -D_REENTRANT -mt -g0 +DA2.0W +DS2.0 +Z -I/rr/h -Wl,+s /rr/lib//liboscfe.a -Wl,-a,default -lpthread -lm -o /rr/dbg//bin/sch2db

Compilation of sch2db requires library liboscfe.a, but I do not want to use -lrt flag here. Without -lrt I am getting errors given below:
......
ld: Unsatisfied symbol "sem_open" in file /rr/lib//liboscfe.a[vsllcr.o]
ld: Unsatisfied symbol "sem_close" in file /rr/lib//liboscfe.a[vsllcr.o]
ld: Unsatisfied symbol "sem_post" in file /rr/lib//liboscfe.a[vsllcr.o]
ld: Unsatisfied symbol "sem_wait" in file /rr/lib//liboscfe.a[vsllcr.o]
4 errors.

Could anybody please suggest a solution?

Thanks!

Any particular reason you can't use -lrt? That's what it's there for.

[edit] More detail

Being your library is static, it can't link to -lrt by itself -- for that matter, it's not linked at all yet, it's just a bundle of object files. If you built a dynamic library instead, it could resolve it's own libraries.