more on undefined reference to 'pg_detoast_datum' and libpq

Apparently in PosgreSQL 7.2.3 (the Redhat 7.3 version, which has some 
patching involved), pg_detoast_datum is defined in fmgr backend code, 
but this function is not defined anywhere in any library, especially not 
libpq. It is the necessity to use fmgr.h functions that brings about the 
need to have pg_detoast_datum. The V1 interface itself requires fmgr.h, 
this is where PG_FUNCTION_INFO_V1 is declared, along with other V1 
macros. My guess is that pg_detoast_datum should be in a library 
somewhere, but manually compiling PostgreSQL 7.2.3 source with 
unstripped libraries shows that no dynamic library produced from the 
source build contains the necessary functions. There does not appear to 
be any libfmgr.so (of any version), unless there is some configure 
option I am missing.

How do I get around this without using non-Redhat packages and without 
forcing users to install another version of PostgreSQL? At this point it 
looks like there is no choice but to use the V0 interface to libpq and 
develop separate projects for other versions of linux PostgreSQL that 
have more recent versions.

D. Stimits