[Buildroot] Buildroot for jffs2 Filesystem fails with zlib.h not found

[Michael Moser]

I try to build a tool chain and initial filesystem for a xscale 
prozessor which uses a jffs2 file system. This fails with the following 
messages:

> make[1]: Entering directory `/home/michael/development/buildroot/toolchain_build_arm/mtd_orig/util'
> gcc -I../include -O2 -Wall -g -c -o mkfs.jffs2.o mkfs.jffs2.c -g -Wp,-MD,.mkfs.jffs2.c.dep
> mkfs.jffs2.c:68:18: zlib.h: File or Directory not found
> make[1]: *** [mkfs.jffs2.o] Error 1
> make[1]: Leaving directory `/home/michael/development/buildroot/toolchain_build_arm/mtd_orig/util'
> make: *** [/home/michael/development/buildroot/toolchain_build_arm/mtd_orig/util/mkfs.jffs2] Fehler 2

If I try to build the same tool chain for ext2 filesystem it succeeds.

I already tried to change the make file and specifed a path to zlib.h 
within the buildroot environment. Then the compilation succeeds but the 
linker didn't find a compatible libz

Can anyone give me some hints?