When setting MYSQL=on it is not able to locate sql.h (in poudriere)

(Be aware, that there is a Bug 203448 from 2015-09-29 with the subject
“Update math/glpk to version 4.55” including a patch!)

...8<---
libtool: compile:  cc -DHAVE_CONFIG_H -I. -I.. -I. -I./amd -I./bflib -I./cglib -I./colamd -I./env -I./minisat -I./misc -I./proxy -I./zlib -I/usr/local/include/mysql -D_LSEEK_DECLARED -I/usr/local/include -O2 -pipe -trigraphs -fstack-protector -fno-strict-aliasing -MT libglpk_la-glpspx02.lo -MD -MP -MF .deps/libglpk_la-glpspx02.Tpo -c glpspx02.c -o libglpk_la-glpspx02.o >/dev/null 2>&1
mv -f .deps/libglpk_la-glpspx02.Tpo .deps/libglpk_la-glpspx02.Plo
/bin/sh ../libtool  --tag=CC   --mode=compile cc -DHAVE_CONFIG_H -I. -I..  -I. -I./amd -I./bflib -I./cglib -I./colamd -I./env -I./minisat -I./misc -I./proxy -I./zlib -I/usr/local/include/mysql -D_LSEEK_DECLARED -I/usr/local/include  -O2 -pipe  -trigraphs -fstack-protector -fno-strict-aliasing -MT libglpk_la-glpsql.lo -MD -MP -MF .deps/libglpk_la-glpsql.Tpo -c -o libglpk_la-glpsql.lo `test -f 'glpsql.c' || echo './'`glpsql.c
libtool: compile:  cc -DHAVE_CONFIG_H -I. -I.. -I. -I./amd -I./bflib -I./cglib -I./colamd -I./env -I./minisat -I./misc -I./proxy -I./zlib -I/usr/local/include/mysql -D_LSEEK_DECLARED -I/usr/local/include -O2 -pipe -trigraphs -fstack-protector -fno-strict-aliasing -MT libglpk_la-glpsql.lo -MD -MP -MF .deps/libglpk_la-glpsql.Tpo -c glpsql.c  -fPIC -DPIC -o .libs/libglpk_la-glpsql.o
In file included from glpsql.c:31:
In file included from ./glpmpl.h:29:
In file included from ./env2.h:8:
./env/env.h:32:9: warning: 'SIZE_T_MAX' macro redefined
#define SIZE_T_MAX (~(size_t)0)
        ^
/usr/include/sys/limits.h:76:9: note: previous definition is here
#define SIZE_T_MAX      __SIZE_T_MAX    /* max value for a size_t */
        ^
glpsql.c:340:10: fatal error: 'sql.h' file not found
#include <sql.h>
         ^
1 warning and 1 error generated.
Makefile:1224: recipe for target 'libglpk_la-glpsql.lo' failed
--->8...

Regards,
 Kalten