How to patch a file that resides in /Applications (patch can't find file to patch at input line)?
I think the problem is that you are not specifying the p option.

From the manual for patch:

For example, supposing the file name  in  the  patch file was

  /u/howard/src/blurfl/blurfl.c

setting -p0 gives the entire file name unmodified, -p1 gives

  u/howard/src/blurfl/blurfl.c

without the leading slash, -p4 gives

  blurfl/blurfl.c

and  not  specifying  -p  at  all just gives you

  blurfl.c.

Whatever you end up with is looked for either in the current directory,
or the directory specified by the -d option.


So the command should be something like:

patch -p0 &lt;custom.patch


or you could specify the directory to which the patch should be applied:

patch -d /path/to/dir &lt;custom.patch