Hunk #1 FAILED at 1. What's that mean?

It is an error generated by patch. If you would open the .patch file, you'd see that it's organized in a bunch of segments, so-called "hunks". Every hunk identifies corresponding pieces of code (by line numbers) in the old and new version, the differences between those pieces of code, and similarities between them (the "context").

A hunk might fail if the similarities of a hunk don't match what's in the original file. When you see this error, it is almost always because you're using a patch for the wrong version of the code you're patching. There are a few ways to work around this:

  • Get an updated version of libdvdnav that already includes the patch (best option).
  • Get a .patch file for the version of libdvdnav you're patching.
  • Patch manually. For every hunk in the patch, try to locate the corresponding file and lines in libdvdnav, and correct them according to the instructions in the patch.
  • Take the version of libdvdnav that's closer to whatever version the .patch file was intended for (probably a bad idea).

In some cases, there is no difference in file versions, but only in indentation, spacing, line ending or line numbers.

To patch despite those differences, it's possible to use the following two arguments :

--ignore-whitespace : It ignores whitespace differences (indentation, etc).

--fuzz 3 : the "--fuzz X" option sets the maximum fuzz factor to lines. This option only applies to context and unified diffs; it ignores up to X lines while looking for the place to install a hunk. Note that a larger fuzz factor increases the odds of making a faulty patch. The default fuzz factor is 2; there is no point to setting it to more than the number of lines of context in the diff, ordinarily 3.

Don't forget to user "--dry-run" : It'll try the patch without applying it.

Example :

patch --verbose --dry-run --ignore-whitespace --fuzz 3 < /path/to/patch.patch

More informations about Fuzz :

https://www.gnu.org/software/diffutils/manual/html_node/Inexact.html


Debugging Tips

  1. Add crlf to the end of the patch file and test if it works
  2. try the --ignore-whitespace command like in: markus@ubuntu:~$ patch -Np1 --ignore-whitespace -d software-1.0 < fix-bug.patch see tutorial by markus