What library uses postmaster when lib postgres files are installed not on library path - Mailing list pgsql-admin

I'm testing 8.1.3 and 8.1.6 of FC3 2.6.12 .
I have installed (compiled from source) two copies of PostgreSQL:
8.1.3 - typically in /usr/local/pgsql and I have configured path to
these libs (in ld.so.conf): /usr/local/pgsql/lib
8.1.6 - not typically in /usr/local/pgsql816 (I edited before installing
with "make install" src/Makefile.global and I changed "prefix" for
install after "configure" and "make")
I never use this two versions of postmaster parallel, so I use for them
this same database cluster.

What libraries uses postmaster 8.1.6 in this situation ? Their own libs
or taken from 8.1.3 ?

Best regards
Adam