BUG #5156: Problem compiling postgresql-8.5alpha2

The following bug has been logged online:

Bug reference: 5156
Logged by: Pierre
Email address: pierre42d(at)9online(dot)fr
PostgreSQL version: 8.5a2
Operating system: GNU/Linux
Description: Problem compiling postgresql-8.5alpha2
Details:

[...]
make -C ../../../src/port all
make[4]: Entering directory `/tmp/postgresql-8.5alpha2/src/port'
make[4]: Nothing to be done for `all'.
make[4]: Leaving directory `/tmp/postgresql-8.5alpha2/src/port'
gcc -s -O3 -march=i686 -Wall -Wmissing-prototypes -Wpointer-arith
-Wdeclaration-after-statement -Wendif-labels -fno-strict-aliasing -fwrapv
-I. -I. -I../../../src/interfaces/libpq -I../../../src/bin/pg_dump
-I../../../src/include -D_GNU_SOURCE -I/usr/local/include/libxml2 -c -o
command.o command.c -MMD -MP -MF .deps/command.Po
In file included from input.h:23,
from command.c:46:
/usr/local/include/readline/history.h:46: error: redefinition of `struct
_hist_entry'
/usr/local/include/readline/history.h:83: error: conflicting types for
'add_history'
/usr/local/include/readline/readline.h:94: error: previous declaration of
'add_history' was here
/usr/local/include/readline/history.h:83: error: conflicting types for
'add_history'
/usr/local/include/readline/readline.h:94: error: previous declaration of
'add_history' was here
make[3]: *** [command.o] Error 1
make[3]: Leaving directory `/tmp/postgresql-8.5alpha2/src/bin/psql'
make[2]: *** [all] Error 2
make[2]: Leaving directory `/tmp/postgresql-8.5alpha2/src/bin'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/tmp/postgresql-8.5alpha2/src'
make: *** [all] Error 2