Cross-compile Apache Portable Runtime to the iPhon

This is a followup to a previous question on cross-compiling for the iPhone:
Cross-compile Autotools-based Libraries for Official iPhone SDK

Basically, I am trying to compile the Apache Portable Runtime (APR) version 1.3.8 (latest) for the iPhone. I am currently running into the following error during the configuration step:

checking for working PROCESS_SHARED locks... configure: error: in `/Users/michaelsafyan/Downloads/apr-1.3.8':
configure: error: cannot run test program while cross compiling
See `config.log' for more details.

I am invoking the "configure" script via "iphone3.1-configure --disable-dso --enable-threads", where "iphone3.1-configure" is the following script that I've cooked-up to invoke the "configure" script:

#! /bin/bash

#
# Program  : iphone3.1-configure
# Authors  : Michael Aaron Safyan (michaelsafyan@gmail.com)
# Synopsis :
#            This program runs the "configure" script generated by the
#            GNU Autotools in order to cross-compile thirdparty libraries
#            for the iPhone 3.1 SDK. Run this script while in a directory
#            containing an autotools "configure" script. Once you run this,
#            you can use "make" and "sudo make install" to build the library.
#            An install prefix of "/opt/iphone-3.1/" is used.
#

unset CPATH
unset C_INCLUDE_PATH
unset CPLUS_INCLUDE_PATH
unset OBJC_INCLUDE_PATH
unset LIBS
unset DYLD_FALLBACK_LIBRARY_PATH
unset DYLD_FALLBACK_FRAMEWORK_PATH

export BUILD_DARWIN_VER=`uname -r`
export SDKVER="3.1"
export DEVROOT="/Developer/Platforms/iPhoneOS.platform/Developer"
export SDKROOT="$DEVROOT/SDKs/iPhoneOS$SDKVER.sdk"
export PKG_CONFIG_PATH=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS$SDKVER.sdk/usr/lib/pkgconfig:/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/pkgconfig:/opt/iphone-$SDKVER/lib/pkgconfig:/usr/local/iphone-$SDKVER/lib/pkgconfig
export PREFIX="/opt/iphone-$SDKVER"
export AS="$DEVROOT/usr/bin/as"
export ASCPP="$DEVROOT/usr/bin/as"
export AR="$DEVROOT/usr/bin/ar"
export RANLIB="$DEVROOT/usr/bin/ranlib"
export CPPFLAGS="-pipe -no-cpp-precomp -I$SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.2.1/include/ -I$SDKROOT/usr/include -I$DEVROOT/usr/include -I/opt/iphone-$SDKVER/include -I/usr/local/iphone-$SDKVER/include"
export CFLAGS="-std=c99 -arch armv6 -pipe -no-cpp-precomp --sysroot='$SDKROOT' -isystem $SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.2.1/include/ -isystem $SDKROOT/usr/include -isystem $DEVROOT/usr/include -isystem /opt/iphone-$SDKVER/include -isystem /usr/local/iphone-$SDKVER/include"
export CXXFLAGS="-std=c99 -arch armv6 -pipe -no-cpp-precomp --sysroot='$SDKROOT' -isystem $SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.2.1/include/ -isystem $SDKROOT/usr/include -isystem $DEVROOT/usr/include -isystem /opt/iphone-$SDKVER/include -isystem /usr/local/iphone-$SDKVER/include"
export LDFLAGS="-arch armv6 --sysroot='$SDKROOT' -L$SDKROOT/usr/lib -L$DEVROOT/usr/lib -L/opt/iphone-$SDKVER/lib -L/usr/local/iphone-$SDKVER/lib"
export CPP="$DEVROOT/usr/bin/cpp"
export CXXCPP="$DEVROOT/usr/bin/cpp"
export CC="$DEVROOT/usr/bin/gcc-4.2"
export CXX="$DEVROOT/usr/bin/g++-4.2"
export LD="$DEVROOT/usr/bin/ld"
export STRIP="$DEVROOT/usr/bin/strip"

if [ ! \( -d "$DEVROOT" \) ] ; then
   echo "The iPhone SDK could not be found. Folder \"$DEVROOT\" does not exist."
   exit 1
fi

if [ ! \( -d "$SDKROOT" \) ] ; then
   echo "The iPhone SDK could not be found. Folder \"$SDKROOT\" does not exist."
   exit 1
fi

./configure --prefix="$PREFIX" --build="i386-apple-darwin$BUILD_DARWIN_VER" --host="arm-apple-darwin9" --enable-static --disable-shared ac_cv_file__dev_zero=no ac_cv_func_setpgrp_void=yes $@

The error that configure is giving me is not the first time I have received a message along the lines of "cannot run test program while cross compiling". In fact, the "ac_cv_file__dev_zero=no" and "ac_cv_func_setpgrp_void=yes" elements in the "iphone3.1-configure" script cause two similarly failing tests to be bypassed. The problem I am having is that I do not know how to bypass this check -- that is, I don't know what variable(s) to set to bypass this test and any additional tests that try to run executables built for the target platform. I was able to bypass the earlier two similar tests simply because I was able to locate the workaround on Google... does anyone know what variables to set or another way to bypass this check?

If anyone knows a way to suppress all tests that cannot be executed when cross-compiling, or if you just know how to suppress this specific check, I would be greatly appreciative. Thank you very much.

The following variables need to be set:

ac_cv_file__dev_zero="yes"
ac_cv_func_setpgrp_void="yes"
apr_cv_process_shared_works="yes"
apr_cv_mutex_robust_shared="no"
apr_cv_tcp_nodelay_with_cork="yes"
ac_cv_sizeof_struct_iovec="8"
apr_cv_mutex_recursive="yes"

Use the following updated "iphone3.1-configure" script to configure the program:

#! /bin/bash

#
# Program  : iphone3.1-configure
# Authors  : Michael Aaron Safyan (michaelsafyan@gmail.com)
# Synopsis :
#            This program runs the "configure" script generated by the
#            GNU Autotools in order to cross-compile thirdparty libraries
#            for the iPhone 3.1 SDK. Run this script while in a directory
#            containing an autotools "configure" script. Once you run this,
#            you can use "make" and "sudo make install" to build the library.
#            An install prefix of "/opt/iphone-3.1/" is used.
#

unset CPATH
unset C_INCLUDE_PATH
unset CPLUS_INCLUDE_PATH
unset OBJC_INCLUDE_PATH
unset LIBS
unset DYLD_FALLBACK_LIBRARY_PATH
unset DYLD_FALLBACK_FRAMEWORK_PATH

export BUILD_DARWIN_VER=`uname -r`
export SDKVER="3.1"
export DEVROOT="/Developer/Platforms/iPhoneOS.platform/Developer"
export SDKROOT="$DEVROOT/SDKs/iPhoneOS$SDKVER.sdk"
export PKG_CONFIG_PATH=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS$SDKVER.sdk/usr/lib/pkgconfig:/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/pkgconfig:/opt/iphone-$SDKVER/lib/pkgconfig:/usr/local/iphone-$SDKVER/lib/pkgconfig
export PREFIX="/opt/iphone-$SDKVER"
export AS="$DEVROOT/usr/bin/as"
export ASCPP="$DEVROOT/usr/bin/as"
export AR="$DEVROOT/usr/bin/ar"
export RANLIB="$DEVROOT/usr/bin/ranlib"
export CPPFLAGS="-pipe -no-cpp-precomp -I$SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.2.1/include/ -I$SDKROOT/usr/include -I$DEVROOT/usr/include -I/opt/iphone-$SDKVER/include -I/usr/local/iphone-$SDKVER/include"
export CFLAGS="-std=c99 -arch armv6 -pipe -no-cpp-precomp --sysroot='$SDKROOT' -isystem $SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.2.1/include/ -isystem $SDKROOT/usr/include -isystem $DEVROOT/usr/include -isystem /opt/iphone-$SDKVER/include -isystem /usr/local/iphone-$SDKVER/include"
export CXXFLAGS="-std=c99 -arch armv6 -pipe -no-cpp-precomp --sysroot='$SDKROOT' -isystem $SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.2.1/include/ -isystem $SDKROOT/usr/include -isystem $DEVROOT/usr/include -isystem /opt/iphone-$SDKVER/include -isystem /usr/local/iphone-$SDKVER/include"
export LDFLAGS="-arch armv6 --sysroot='$SDKROOT' -L$SDKROOT/usr/lib -L$DEVROOT/usr/lib -L/opt/iphone-$SDKVER/lib -L/usr/local/iphone-$SDKVER/lib"
export CPP="$DEVROOT/usr/bin/cpp"
export CXXCPP="$DEVROOT/usr/bin/cpp"
export CC="$DEVROOT/usr/bin/gcc-4.2"
export CXX="$DEVROOT/usr/bin/g++-4.2"
export LD="$DEVROOT/usr/bin/ld"
export STRIP="$DEVROOT/usr/bin/strip"

if [ ! \( -d "$DEVROOT" \) ] ; then
   echo "The iPhone SDK could not be found. Folder \"$DEVROOT\" does not exist."
   exit 1
fi

if [ ! \( -d "$SDKROOT" \) ] ; then
   echo "The iPhone SDK could not be found. Folder \"$SDKROOT\" does not exist."
   exit 1
fi

./configure \
    --prefix="$PREFIX" \
    --build="i386-apple-darwin$BUILD_DARWIN_VER" \
    --host="arm-apple-darwin9" \
    --enable-static \
    --disable-shared \
    ac_cv_file__dev_zero="yes" \
    ac_cv_func_setpgrp_void="yes" \
    apr_cv_process_shared_works="yes" \
    apr_cv_mutex_robust_shared="no" \
    apr_cv_tcp_nodelay_with_cork="yes" \
    ac_cv_sizeof_struct_iovec="8" \
    apr_cv_mutex_recursive="yes" $@

Use "iphone3.1-configure --disable-dso --enable-threads && make", then "sudo make install".