Build problem

[James Yates]

During a build I get the following error and I can't work out why. I can compile this in exactly the same way 
on another PC with an identical cygwin and rtems directories and it works fine. Can anyone help?

I have included the output below:

checking for sh-rtems-strip... (cached) sh-rtems-strip
checking if wanting multiprocessing... no
configure: creating ./config.status
configure: configuring in ../../cpukit
configure: running /bin/bash '/opt/rtems/rtems-4.6.0/c/src/../../cpukit/configure'  '--prefix=/opt/rtems/builds/fu0018' '--host=sh-rtems' '--build=i686-pc-cygwin' '--target=sh-rtem
s' '--disable-posix' '--disable-networking' '--disable-cxx' '--with-target-subdir=sh-rtems' '--exec-prefix=/opt/rtems/builds/fu0018/sh-rtems' 'build_alias=i686-pc-cygwin' 'host_ali
as=sh-rtems' 'target_alias=sh-rtems' 'RTEMS_BSP=fu0018' 'RTEMS_CPU_MODEL=sh7145' 'RTEMS_BSP_FAMILY=fu0018' 'CPU_CFLAGS=-m2' 'CFLAGS_OPTIMIZE_V=-O1' 'CFLAGS_DEBUG_V=-O1 -g' '--with-
project-root=../../' '--enable-rtemsbsp=fu0018'
   --cache-file=/dev/null --srcdir=/opt/rtems/rtems-4.6.0/c/src/../../cpukit
configure: error: invalid variable name: build_alias
configure: error: /bin/bash '/opt/rtems/rtems-4.6.0/c/src/../../cpukit/configure' failed for ../../cpukit
make[2]: *** [fu0018] Error 1
make[2]: Leaving directory `/opt/rtems/builds/temp/build-fu0018/sh-rtems/c'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/opt/rtems/builds/temp/build-fu0018/sh-rtems/c'
make: *** [all-recursive] Error 1
Making all in make
make[1]: Entering directory `/opt/rtems/builds/temp/build-fu0018/make'
Making all in custom
make[2]: Entering directory `/opt/rtems/builds/temp/build-fu0018/make/custom'
make[2]: Nothing to be done for `all'.
make[2]: Leaving directory `/opt/rtems/builds/temp/build-fu0018/make/custom'
make[2]: Entering directory `/opt/rtems/builds/temp/build-fu0018/make'
make[2]: Nothing to be done for `all-am'.
make[2]: Leaving directory `/opt/rtems/builds/temp/build-fu0018/make'
make[1]: Leaving directory `/opt/rtems/builds/temp/build-fu0018/make'