Build of clamz with musl toolchain

# [tuscan]
# Server = file:///var/cache/pacman/pkg/

# :: Synchronizing package databases...
# downloading tuscan.db...

# /sysroot/lib
# /sysroot/share
# /sysroot/bin
# /sysroot/include
# /sysroot/libexec

# ==> Making package: clamz 0.5-3 (Wed Apr 5 02:13:22 UTC 2017)
# ==> Checking runtime dependencies...
# ==> Checking buildtime dependencies...
# ==> WARNING: Using existing $srcdir/ tree
# ==> Starting build()...
# configure: WARNING: if you wanted to set the --build type, don't use --host.
# If a cross compiler is detected then cross compile mode will be used
# checking for x86_64-unknown-linux-gcc... clang
# checking whether the C compiler works... yes
# checking for C compiler default output file name... a.out
# checking for suffix of executables...
# checking whether we are cross compiling... yes
# checking for suffix of object files... o
# checking whether we are using the GNU C compiler... yes
# checking whether clang accepts -g... yes
# checking for clang option to accept ISO C89... none needed
# checking for a BSD-compatible install... /usr/bin/install -c
# checking for update-mime-database... update-mime-database
# checking for update-desktop-database... update-desktop-database
# checking for XML_ParserCreate in -lexpat... no
# configure: error: libexpat not found
# ==> ERROR: A failure occurred in build().
# Aborting...

# This file contains any messages produced by compilers while
# running configure, to aid debugging if configure makes a mistake.
#
# It was created by Clamz configure 0.5, which was
# generated by GNU Autoconf 2.68. Invocation command line was
#
# $ ./configure --host=x86_64-unknown-linux --prefix=/usr/
#
# ## --------- ##
# ## Platform. ##
# ## --------- ##
#
# hostname = 9df70a91aa43
# uname -m = x86_64
# uname -r = 4.10.6-1-ARCH
# uname -s = Linux
# uname -v = #1 SMP PREEMPT Mon Mar 27 08:28:22 CEST 2017
#
# /usr/bin/uname -p = unknown
# /bin/uname -X = unknown
#
# /bin/arch = unknown
# /usr/bin/arch -k = unknown
# /usr/convex/getsysinfo = unknown
# /usr/bin/hostinfo = unknown
# /bin/machine = unknown
# /usr/bin/oslevel = unknown
# /bin/universe = unknown
#
# PATH: /sysroot/bin
# PATH: /usr/local/sbin
# PATH: /usr/local/bin
# PATH: /usr/sbin
# PATH: /usr/bin
# PATH: /sbin
# PATH: /bin
#
#
# ## ----------- ##
# ## Core tests. ##
# ## ----------- ##
#
# configure:2022: checking for x86_64-unknown-linux-gcc
# configure:2049: result: clang
# configure:2318: checking for C compiler version
# configure:2327: clang --version >&5
# clang version 3.8.1
# Target: x86_64-unknown-linux-gnu
# Thread model: posix
# InstalledDir: /
# configure:2338: $? = 0
# configure:2327: clang -v >&5
# clang version 3.8.1
# Target: x86_64-unknown-linux-gnu
# Thread model: posix
# InstalledDir: /
# Found candidate GCC installation: //../lib/gcc/x86_64-pc-linux-gnu/6.1.1
# Found candidate GCC installation: //../lib64/gcc/x86_64-pc-linux-gnu/6.1.1
# Selected GCC installation: //../lib64/gcc/x86_64-pc-linux-gnu/6.1.1
# Candidate multilib: .;@m64
# Selected multilib: .;@m64
# configure:2338: $? = 0
# configure:2327: clang -V >&5
# clang-3.8: error: argument to '-V' is missing (expected 1 value)
# clang-3.8: error: no input files
# configure:2338: $? = 1
# configure:2327: clang -qversion >&5
# clang-3.8: error: unknown argument: '-qversion'
# clang-3.8: error: no input files
# configure:2338: $? = 1
# configure:2358: checking whether the C compiler works
# configure:2380: clang conftest.c >&5
# configure:2384: $? = 0
# configure:2432: result: yes
# configure:2435: checking for C compiler default output file name
# configure:2437: result: a.out
# configure:2443: checking for suffix of executables
# configure:2450: clang -o conftest conftest.c >&5
# configure:2454: $? = 0
# configure:2476: result:
# configure:2498: checking whether we are cross compiling
# configure:2506: clang -o conftest conftest.c >&5
# configure:2510: $? = 0
# configure:2517: ./conftest
# ./conftest: error while loading shared libraries: /usr/lib/libc.so: invalid ELF header
# configure:2521: $? = 127
# configure:2536: result: yes
# configure:2541: checking for suffix of object files
# configure:2563: clang -c conftest.c >&5
# configure:2567: $? = 0
# configure:2588: result: o
# configure:2592: checking whether we are using the GNU C compiler
# configure:2611: clang -c conftest.c >&5
# configure:2611: $? = 0
# configure:2620: result: yes
# configure:2629: checking whether clang accepts -g
# configure:2649: clang -c -g conftest.c >&5
# configure:2649: $? = 0
# configure:2690: result: yes
# configure:2707: checking for clang option to accept ISO C89
# configure:2771: clang -c conftest.c >&5
# configure:2771: $? = 0
# configure:2784: result: none needed
# configure:2850: checking for a BSD-compatible install
# configure:2918: result: /usr/bin/install -c
# configure:2933: checking for update-mime-database
# configure:2949: found /usr/sbin/update-mime-database
# configure:2961: result: update-mime-database
# configure:2973: checking for update-desktop-database
# configure:2989: found /usr/sbin/update-desktop-database
# configure:3001: result: update-desktop-database
# configure:3012: checking for XML_ParserCreate in -lexpat
# configure:3037: clang -o conftest -W -Wall conftest.c -lexpat >&5
# /sysroot/bin/ld: error: cannot find -lexpat
# /tmp/conftest-a68764.o:conftest.c:function main: error: undefined reference to 'XML_ParserCreate'
# clang-3.8: error: linker command failed with exit code 1 (use -v to see invocation)
# configure:3037: $? = 1
# configure: failed program was:
# | /* confdefs.h */
# | #define PACKAGE_NAME "Clamz"
# | #define PACKAGE_TARNAME "clamz"
# | #define PACKAGE_VERSION "0.5"
# | #define PACKAGE_STRING "Clamz 0.5"
# | #define PACKAGE_BUGREPORT "floppusmaximus@users.sf.net"
# | #define PACKAGE_URL ""
# | /* end confdefs.h. */
# |
# | /* Override any GCC internal prototype to avoid an error.
# | Use char because int might match the return type of a GCC
# | builtin and then its argument prototype would still apply. */
# | #ifdef __cplusplus
# | extern "C"
# | #endif
# | char XML_ParserCreate ();
# | int
# | main ()
# | {
# | return XML_ParserCreate ();
# | ;
# | return 0;
# | }
# configure:3046: result: no
# configure:3056: error: libexpat not found
#
# ## ---------------- ##
# ## Cache variables. ##
# ## ---------------- ##
#
# ac_cv_c_compiler_gnu=yes
# ac_cv_env_CC_set=set
# ac_cv_env_CC_value=clang
# ac_cv_env_CFLAGS_set=set
# ac_cv_env_CFLAGS_value=
# ac_cv_env_CPPFLAGS_set=set
# ac_cv_env_CPPFLAGS_value=
# ac_cv_env_CPP_set=
# ac_cv_env_CPP_value=
# ac_cv_env_LDFLAGS_set=set
# ac_cv_env_LDFLAGS_value=
# ac_cv_env_LIBCURL_CFLAGS_set=
# ac_cv_env_LIBCURL_CFLAGS_value=
# ac_cv_env_LIBCURL_LIBS_set=
# ac_cv_env_LIBCURL_LIBS_value=
# ac_cv_env_LIBGCRYPT_CFLAGS_set=
# ac_cv_env_LIBGCRYPT_CFLAGS_value=
# ac_cv_env_LIBGCRYPT_LIBS_set=
# ac_cv_env_LIBGCRYPT_LIBS_value=
# ac_cv_env_LIBS_set=
# ac_cv_env_LIBS_value=
# ac_cv_env_PKG_CONFIG_set=
# ac_cv_env_PKG_CONFIG_value=
# ac_cv_env_UPDATE_DESKTOP_DATABASE_set=
# ac_cv_env_UPDATE_DESKTOP_DATABASE_value=
# ac_cv_env_UPDATE_MIME_DATABASE_set=
# ac_cv_env_UPDATE_MIME_DATABASE_value=
# ac_cv_env_build_alias_set=
# ac_cv_env_build_alias_value=
# ac_cv_env_host_alias_set=set
# ac_cv_env_host_alias_value=x86_64-unknown-linux
# ac_cv_env_target_alias_set=
# ac_cv_env_target_alias_value=
# ac_cv_lib_expat_XML_ParserCreate=no
# ac_cv_objext=o
# ac_cv_path_install='/usr/bin/install -c'
# ac_cv_prog_CC=clang
# ac_cv_prog_UPDATE_DESKTOP_DATABASE=update-desktop-database
# ac_cv_prog_UPDATE_MIME_DATABASE=update-mime-database
# ac_cv_prog_cc_c89=
# ac_cv_prog_cc_g=yes
#
# ## ----------------- ##
# ## Output variables. ##
# ## ----------------- ##
#
# CC='clang'
# CFLAGS=' -W -Wall'
# CPP=''
# CPPFLAGS=''
# DEFS=''
# ECHO_C=''
# ECHO_N='-n'
# ECHO_T=''
# EGREP=''
# EXEEXT=''
# GREP=''
# INSTALL_DATA='${INSTALL} -m 644'
# INSTALL_PROGRAM='${INSTALL}'
# INSTALL_SCRIPT='${INSTALL}'
# LDFLAGS=''
# LIBCURL_CFLAGS=''
# LIBCURL_LIBS=''
# LIBGCRYPT_CFLAGS=''
# LIBGCRYPT_CONFIG=''
# LIBGCRYPT_LIBS=''
# LIBOBJS=''
# LIBS=''
# LTLIBOBJS=''
# OBJEXT='o'
# PACKAGE_BUGREPORT='floppusmaximus@users.sf.net'
# PACKAGE_NAME='Clamz'
# PACKAGE_STRING='Clamz 0.5'
# PACKAGE_TARNAME='clamz'
# PACKAGE_URL=''
# PACKAGE_VERSION='0.5'
# PATH_SEPARATOR=':'
# PKG_CONFIG=''
# SHELL='/bin/sh'
# UPDATE_DESKTOP_DATABASE='update-desktop-database'
# UPDATE_MIME_DATABASE='update-mime-database'
# ac_ct_CC=''
# bindir='${exec_prefix}/bin'
# build_alias=''
# datadir='${datarootdir}'
# datarootdir='${prefix}/share'
# docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
# dvidir='${docdir}'
# exec_prefix='NONE'
# host_alias='x86_64-unknown-linux'
# htmldir='${docdir}'
# includedir='${prefix}/include'
# infodir='${datarootdir}/info'
# libdir='${exec_prefix}/lib'
# libexecdir='${exec_prefix}/libexec'
# localedir='${datarootdir}/locale'
# localstatedir='${prefix}/var'
# mandir='${datarootdir}/man'
# oldincludedir='/usr/include'
# pdfdir='${docdir}'
# prefix='/usr'
# program_transform_name='s,x,x,'
# psdir='${docdir}'
# sbindir='${exec_prefix}/sbin'
# sharedstatedir='${prefix}/com'
# sysconfdir='${prefix}/etc'
# target_alias=''
#
# ## ----------- ##
# ## confdefs.h. ##
# ## ----------- ##
#
# /* confdefs.h */
# #define PACKAGE_NAME "Clamz"
# #define PACKAGE_TARNAME "clamz"
# #define PACKAGE_VERSION "0.5"
# #define PACKAGE_STRING "Clamz 0.5"
# #define PACKAGE_BUGREPORT "floppusmaximus@users.sf.net"
# #define PACKAGE_URL ""
#
# configure: exit 1