I copied also the headers.
I know passed --target=x86_64-linux-musl --build=x86_64-linux-musl --host=x86_64-linux-musl
to configure as well.
In configure it states that it can't find the libz.so, which is the reason for termination.

There is also a folder lib in /opt/cross/x86_64-linux-musl/ (so one level higher) do i have to copy the lib in there as well?

2015-11-18 12:03 GMT+01:00 Szabolcs Nagy <nsz@port70.net>:
* Frieder Berthold <berthold.frieder@googlemail.com> [2015-11-18 11:28:04 +0100]:
> I copied the zlib into /opt/cross/x86_64-linux-mus/x86_64-linux-musl/lib

i assume you also copied the headers to include/

> and run configure on jamVM:
> CC=/opt/cross/x86_64-linux-musl/bin/x86_64-linux-musl-gcc ./autogen.sh
> --with-java-runtime-library=openjdk8
>

you may need to pass --target=x86_64-linux-musl somewhere

> It tells me, that it can't find the libz.so.
>
> So my question is: Is this the right way to configure and where does it
> look for the libz.so if not in the corresponding lib folder of the
> cross-compiler?
>

autogen.sh can fail for any reason, you should look at
the failing command (e.g. in configure.log), most
likely the failure is completely unrelated to libz.so