BUG #2436: cannot --enable-thread-safety on -lpthread host

The following bug has been logged online:

Bug reference: 2436
Logged by: Paul Forgey
Email address: paulf(at)aphrodite(dot)com
PostgreSQL version: 8.1.3
Operating system: Debian stable (sarge)
Description: cannot --enable-thread-safety on -lpthread host
Details:

Linux supplies -lpthread. The configure script seems to only look for
-lpthreads and then give up. I'm surprised to not find anything about this
on the mailing list archives.

configure:16421: checking for the pthreads library -lpthreads
configure:16459: gcc -o conftest -O2 -Wall -Wmissing-prototypes
-Wpointer-arith
-Winline -Wendif-labels -fno-strict-aliasing -D_GNU_SOURCE conftest.c
-lpth
reads -lz -lreadline -lcrypt -lresolv -lnsl -ldl -lm >&5
conftest.c: In function `main':
conftest.c:124: warning: `th' might be used uninitialized in this function
/usr/bin/ld: cannot find -lpthreads
collect2: ld returned 1 exit status
configure:16465: $? = 1