I'm wondering if the undefined libiconv symbols occur as the
expected result of the failure of the conftest test program that is
run to check for the Qt 4 library name? That is libiconv is not
necessarily needed for lyx but is needed for the successful
completion of the check for the "Qt 4 library name" conftest program.
Perhaps including libiconf in LDFLAGS defeats the purpose of the
conftest program.
I'm just guessing this might be what's happening as I'm not good
enough at reading the configure script to be sure.
Relevant extract from your config.log:
configure:24468: checking for Qt 4 library name
configure:24517: g++ -o conftest -g -Os -I/usr/local/QT4//include -I/
usr/local/QT4//include/Qt -I/usr/local/QT4//include/QtCore -I/usr/
local/QT4//include/QtGui -L/usr/local/QT4//lib -Wextra -Wall -
framework Carbon -framework OpenGL -framework AGL -framework
QuickTime -lz -framework Cocoa conftest.cpp -lc -lm -lQtCore >&5
/usr/bin/ld: Undefined symbols:
_libiconv
_libiconv_close
_libiconv_open
collect2: ld returned 1 exit status
Regards
Roger
