OSX Undefined symbols for libiconv

[John Talbot]

I found this issue on OSX 10.13.5 compiling inkscape-0.92.3.

[ 88%] Linking CXX shared library ../lib/libinkscape_base.dylib
Undefined symbols for architecture x86_64:
  "_libiconv", referenced from:
      _U_Utf32leToUtf16le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf16leToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Latin1ToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf8ToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf32leToUtf8 in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf8ToUtf16le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf16leToUtf8 in libuemf_LIB.a(uemf_utf.c.o)
      ...
  "_libiconv_close", referenced from:
      _U_Utf32leToUtf16le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf16leToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Latin1ToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf8ToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf32leToUtf8 in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf8ToUtf16le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf16leToUtf8 in libuemf_LIB.a(uemf_utf.c.o)
      ...
  "_libiconv_open", referenced from:
      _U_Utf32leToUtf16le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf16leToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Latin1ToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf8ToUtf32le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf32leToUtf8 in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf8ToUtf16le in libuemf_LIB.a(uemf_utf.c.o)
      _U_Utf16leToUtf8 in libuemf_LIB.a(uemf_utf.c.o)
      ...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [lib/libinkscape_base.dylib] Error 1
make[1]: *** [src/CMakeFiles/inkscape_base.dir/all] Error 2
make: *** [all] Error 2

There is no /usr/local/include/iconv.h

There is a /usr/include/iconv.h
It does not have the define iconv_t but has instead
typedef void* iconv_t

There is a MacPorts file /opt/local/include/iconv.h which does have the line:
#define iconv_t libiconv_t
MacPorts libconv cannot be removed as it is used by many other packages to compile Inkscape.

port info libiconv returns the latest being->
libiconv @1.15 (textproc)
Variants: cp932fix, universal

Description: A character-set conversion library which implements the iconv() API for dealing
                      with unicode and other types of conversion.
Homepage: https://www.gnu.org/software/libiconv/

Build Dependencies: gperf
Platforms: darwin, freebsd, linux
License: (LGPL-2+ or GPL-3+)
Maintainers: Email: <email address hidden>

Configuration was done for Inkscape using the documented process of:
mkdir build
cd build
cmake ..
make

cmake displays
-- Performing Test ICONV_SECOND_ARGUMENT_IS_CONST
-- Performing Test ICONV_SECOND_ARGUMENT_IS_CONST - Failed
-- Found Iconv: /usr/lib/libiconv.dylib

printenv of my environment returns:
TERM_PROGRAM=Apple_Terminal
TERM=xterm-256color
SHELL=/bin/bash
TMPDIR=/var/folders/pn/_6h1_7g13v7c3tgr7q8qqw5m0000gn/T/
Apple_PubSub_Socket_Render=/private/tmp/com.apple.launchd.aMHZg9YphM/Render
TERM_PROGRAM_VERSION=404
OLDPWD=/Users/me/Downloads/inkscape-0.92.3/src
TERM_SESSION_ID=E5822A4E-4DFD-41CC-BE6B-76135933D46A
USER=me
SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.2qSrDHNG6w/Listeners
PATH=/opt/local/bin:/opt/local/sbin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
PWD=/Users/me/Downloads/inkscape-0.92.3
LANG=en_CA.UTF-8
XPC_FLAGS=0x0
XPC_SERVICE_NAME=0
HOME=/Users/me
SHLVL=1
LOGNAME=me
_=/usr/bin/printenv

I did a git clone of https://gitlab.com/inkscape/inkscape.git
cmake reports the same for iconv, but I cannot get past make as the port for gdl fails to compile and is required for the latest Inkscape.

For what I understand so far, those undefined symbols are defined in /opt/local/lib/libiconv.dylib
but cmake picks up /usr/lib/libiconv.dylib and then the compile uses /opt/local/include/iconv.h and all the associated symbols that /usr/lib/libiconv.dylib does not have.

I resolved the issue temporarily by from the bash prompt first setting
CMAKE_PREFIX_PATH="/opt/local/lib/"
This could be the solution for those compiling from OSX with MacPorts installed. The documentation would then just have to be changed to reflect this.

Cheers,
John Talbot