Building GHC as a cross-compiler for armhf fails with undefined reference to `dlopen', `dlerror', `dlsym'

Running on Ubuntu 14.04.1 I am trying to build a stage1 cross-compiler for a Raspberry Pi running Raspbian. I am using the tool chain located at https://github.com/raspberrypi/tools.

I copied my Raspberry Pi's /include and /usr directories to my build machine into directory /home/johnma/rpi-toolchain/rootfs.

Following these instructions https://ghcarm.wordpress.com/2014/01/18/unregisterised-ghc-head-build-for-arm64-platform/ I force gcc to use my sysroot using this bash script:

/home/johnma/mygcc contains: {{{ #!/bin/bash arm-linux-gnueabihf-gcc --sysroot=/home/johnma/rpi-toolchain/rootfs $@ }}}

My mk/build.mk file contains:

# Fast build configured for a cross compiler
BuildFlavour  = quick-cross

I used this configure command:

./configure --target=arm-linux-gnueabihf --enable-unregisterised --with-gcc=/home/johnma/mygcc --with-nm=/usr/bin/nm

The build ends with:

"inplace/bin/ghc-stage1" -o utils/hsc2hs/dist-install/build/tmp/hsc2hs -hisuf hi -osuf  o -hcsuf hc -static  -H64m -O0    -hide-all-packages -i -iutils/hsc2hs/. -iutils/hsc2hs/dist-install/build -iutils/hsc2hs/dist-install/build/autogen -Iutils/hsc2hs/dist-install/build -Iutils/hsc2hs/dist-install/build/autogen     -optP-include -optPutils/hsc2hs/dist-install/build/autogen/cabal_macros.h -package base-4.7.0.1 -package containers-0.5.5.1 -package directory-1.2.1.0 -package filepath-1.3.0.2 -package process-1.2.0.0 -XHaskell98 -XCPP -XForeignFunctionInterface  -no-user-package-db -rtsopts      -odir utils/hsc2hs/dist-install/build -hidir utils/hsc2hs/dist-install/build -stubdir utils/hsc2hs/dist-install/build   -optl-L'/home/johnma/ghc/libraries/process/dist-install/build' -optl-L'/home/johnma/ghc/libraries/directory/dist-install/build' -optl-L'/home/johnma/ghc/libraries/unix/dist-install/build' -optl-L'/home/johnma/ghc/libraries/time/dist-install/build' -optl-L'/home/johnma/ghc/libraries/old-locale/dist-install/build' -optl-L'/home/johnma/ghc/libraries/filepath/dist-install/build' -optl-L'/home/johnma/ghc/libraries/containers/dist-install/build' -optl-L'/home/johnma/ghc/libraries/bytestring/dist-install/build' -optl-L'/home/johnma/ghc/libraries/deepseq/dist-install/build' -optl-L'/home/johnma/ghc/libraries/array/dist-install/build' -optl-L'/home/johnma/ghc/libraries/base/dist-install/build' -optl-L'/home/johnma/ghc/libraries/integer-simple/dist-install/build' -optl-L'/home/johnma/ghc/libraries/ghc-prim/dist-install/build' -optl-L'/home/johnma/ghc/rts/dist/build' -optl-lrt -optl-lutil -optl-lpthread -optl-lm -optl-lrt -static  -H64m -O0    -hide-all-packages -i -iutils/hsc2hs/. -iutils/hsc2hs/dist-install/build -iutils/hsc2hs/dist-install/build/autogen -Iutils/hsc2hs/dist-install/build -Iutils/hsc2hs/dist-install/build/autogen     -optP-include -optPutils/hsc2hs/dist-install/build/autogen/cabal_macros.h -package base-4.7.0.1 -package containers-0.5.5.1 -package directory-1.2.1.0 -package filepath-1.3.0.2 -package process-1.2.0.0 -XHaskell98 -XCPP -XForeignFunctionInterface  -no-user-package-db -rtsopts      utils/hsc2hs/dist-install/build/Main.o utils/hsc2hs/dist-install/build/HSCParser.o utils/hsc2hs/dist-install/build/DirectCodegen.o utils/hsc2hs/dist-install/build/CrossCodegen.o utils/hsc2hs/dist-install/build/UtilsCodegen.o utils/hsc2hs/dist-install/build/Common.o utils/hsc2hs/dist-install/build/C.o utils/hsc2hs/dist-install/build/Flags.o utils/hsc2hs/dist-install/build/Paths_hsc2hs.o
/home/johnma/ghc/rts/dist/build/libHSrts.a(Linker.o): In function `internal_dlopen':
Linker.c:(.text+0x68): undefined reference to `dlopen'
Linker.c:(.text+0xa4): undefined reference to `dlerror'
/home/johnma/ghc/rts/dist/build/libHSrts.a(Linker.o): In function `lookupSymbol':
Linker.c:(.text+0x874): undefined reference to `dlerror'
Linker.c:(.text+0x89c): undefined reference to `dlsym'
Linker.c:(.text+0x8a4): undefined reference to `dlerror'
Linker.c:(.text+0x8c4): undefined reference to `dlsym'
collect2: error: ld returned 1 exit status
make[1]: *** [utils/hsc2hs/dist-install/build/tmp/hsc2hs] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [all] Error 2