Error Build Image

[nevyen]

Hey I wan't to build this image for my own.
It's because I need to define a diffrent charset.

But if I try to run docker build . I get the error

Step 5/8 : RUN /assets/setup.sh
 ---> Running in 072e9066d1c6
�[91m/assets/setup.sh: line 1: set: -
: invalid option
set: usage: set [-abefhkmnptuvxBCHP] [-o option-name] [--] [arg ...]
docker : The command '/bin/sh -c /assets/setup.sh' returned a non-zero code: 2
In Zeile:1 Zeichen:1
+ docker build .
+ ~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (The command '/b...on-zero code: 2:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

Is there any option to run the build by myself?