I am working on the cross-base patch so we can merge it with wip-hurd as
well, but some problems need to be discussed.

First, in glibc/hurd headers we need to redeclare #:configure-flags with
less flags.
We shouldn't but because we use the same configure flags as in glibc and
glibc/hurd, we get an error at (string-append "--localedir=" (assoc-ref
%outputs "locales") "/share/locale") when it tries to find the locales
output.
>In unknown file:
>   ?: 0 [string-append "--localedir=" #f "/share/locale"]

I attached the log.

Second, in glibc/hurd headers again, because we Don't use the same phases
as in glibc and glibc/hurd, and as a result we don't have the pre-configure
phase of glibc,  /bin/pwd is not substituted with pwd and we get a "no such
file" error.

>checking for i686-pc-gnu-readelf... i686-pc-gnu-readelf
>../glibc-hurd-2.18/configure: line 3312: /bin/pwd: No such file or
directory
>../glibc-hurd-2.18/configure: line 3312: /bin/pwd: No such file or
directory
>configure: error: you must configure in a separate build directory
>phase `configure' failed after 1 seconds

In order to solve this I just need to add a pre-configure phase with just
(lambda _
    (substitute* "configure"
        (("/bin/pwd") "pwd")))

attached log.

Third, in glibc/hurd the permissions in chmod "bits/pthreadtypes.h" should
be 666 not 555.

With this changes glibc/hurd can be built using the i686-pc-gnu cross
toolchain.

I attached the patch and I made sure that there will be no regressions with
the cross-base patch.

I wrote a simple commit message because it needs to be merged with the
current glibc/hurd patch in wip-hurd.

Thank you,
Manolis