linux flex gcc compile fails with `undefined reference to `TclReError'` - c++

Question

I am having some issues compiling flex from source. The configure is being passed
CC=/home/mybin/bin/gcc CPPFLAGS=-I/home/mybin/include LDFLAGS=-L/home/mybin/lib.
Within ../include i have two files containing references
regex.h:110:#define regerror TclReError
regcustom.h:78:#define regerror TclReError
when running config, no error is produced and nothing of interest in the logs, however make throws an error
/bin/sh ../libtool --tag=CC --mode=link /home/mybin/bin/gcc -g -O2 -L/home/mybin/lib -o flex ccl.o dfa.o ecs.o scanflags.o gen.o main.o misc.o nfa.o parse.o scan.o skel.o sym.o tblcmp.o yylex.o options.o scanopt.o buf.o tables.o tables_shared.o filter.o regex.o ../lib/libcompat.la -lm
libtool: link: /home/mybin/bin/gcc -g -O2 -o flex ccl.o dfa.o ecs.o scanflags.o gen.o main.o misc.o nfa.o parse.o scan.o skel.o sym.o tblcmp.o yylex.o options.o scanopt.o buf.o tables.o tables_shared.o filter.o regex.o -L/home/_bin/lib ../lib/.libs/libcompat.a -lm
regex.o: In function `flex_regcomp':
/home/tmp/flex-2.6.0/src/regex.c:66: undefined reference to `TclReError'
collect2: error: ld returned 1 exit status
make[2]: *** [flex] Error 1
in configure --help no reference is made to explicit flags
Some influential environment variables:
CC C compiler command
CFLAGS C compiler flags
LDFLAGS linker flags, e.g. -L<lib dir> if you have libraries in a
nonstandard directory <lib dir>
LIBS libraries to pass to the linker, e.g. -l<library>
CPPFLAGS (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
LT_SYS_LIBRARY_PATH
User-defined run-time library search path.
CPP C preprocessor
YACC The `Yet Another Compiler Compiler' implementation to use.
Defaults to the first program found out of: `bison -y', `byacc',
`yacc'.
YFLAGS The list of arguments that will be passed by default to $YACC.
This script will default YFLAGS to the empty string to avoid a
default value of `-d' given by some make applications.
CXX C++ compiler command
CXXFLAGS C++ compiler flags
CXXCPP C++ preprocessor
I have also tried exporting directly with export CPPFLAGS="-I/home/mybin/include"
extended searches on SO and google have returned noting obvious, any pointers on what I am missing?

Answer 1

you set them as an environment variable; configure determines LDFLAGS and CPPFLAGS by checking config files and the environment. You can try like this.
export CPPFLAGS='-I/home/mybin/include'
export LDFLAGS='-L/home/mybin/lib'
./configure
or as a one-liner:
env CPPFLAGS='-I/home/mybin/include' LDFLAGS='-L/home/mybin/lib' ./configure
Please try this...