guile 1.5.4: libltdl configure fails when CFLAGS set

[Ola Rinta-Koski]

  guile 1.5.4 can't be configured with

env CPPFLAGS=-I/cyber/include CFLAGS="-I/cyber/include -L/cyber/lib" 
CXXFLAGS=$CFLAGS LIBS=-L/cyber/lib ./configure --prefix=/cyber

(...)
configure: configuring in libltdl
configure: running /bin/sh './configure'  --prefix=/cyber 
'CFLAGS=-I/cyber/include -L/cyber/lib' CPPFLAGS=-I/cyber/include CXXFLAGS= 
--enable-ltdl-convenience --cache-file=/dev/null --srcdir=.
configure: warning: CFLAGS=-I/cyber/include -L/cyber/lib: invalid host type
configure: warning: CPPFLAGS=-I/cyber/include: invalid host type
configure: error: can only configure for one host and one target at a time
configure: error: /bin/sh './configure' failed for libltdl
sed: can't read confdefs.h: No such file or directory

  environment: Linux 2.4.16, gcc 2.95.3, zsh 3.1.9
-- 
        Ola Rinta-Koski                                 address@hidden
        Cyberell Oy                                     +358 41 467 2502
        Rauhankatu 8 C, FIN-00170 Helsinki, FINLAND     www.cyberell.com