Error when trying to patch kernel

I’m trying to acs patch my kernel , Ive added the patch to my pkgbuild directory and source to my pkgbuild file and updated by sha 265 checksums , but a few minutes into the patching I get this error:

==> ERROR: A failure occurred in prepare().

I’ll say:
not enough information
… patching doesn’t take minutes but mere seconds
patching is done at the beginning of the process - look for possible issues there

I’d first try building (whatever you are building) without the patch - to narrow the issue down to the patch …