# Quick porting guide for simple packages

*If you want to help port a package with simple issues to the Hurd, please read on.*

*just imagine joe C-doodler stumbling over some GNU philosophy and thinking “hey, I’ve got 2 free hours, why not help the Hurd?”*
*for him I’d like to have a guide (and for me, the faulty-memory-does-too-many-things :) )*

*a short guide “how to do simple ports” broken down to command line level: how to get the list of simple packages (youpi told me that here), how to get the source, how to test the fix, how to submit the fix.*

## Setup an instant Hurd development environment

See [[Instant Development Environment|contributing#index5h2]] - just follow the command to get a Hurd running in Qemu.

## Getting the list of failed packages

    wget http://people.debian.org/~sthibault/failed_packages.txt.gz
    gunzip failed_packages.txt.gz

## Finding a simple task

    grep PATH_MAX failed_packages.txt -B 2

Each of these packages is likely to be simple to fix. The output looks like this: 

    …
    --
    tex/lilypond_2.12.3-7 by buildd_hurd-i386-mozart [optional:uncompiled:bp{-100}:calprio{-63}:days{258}]
      Reasons for failing:
    > file-name.cc:88: error: 'PATH_MAX' was not declared in this scope
    --
    …

in this case, lilypond is the package.

Other simple tasks can be found on [[hurd/porting/guidelines]].

## Downloading the package source and installing dependencies

    apt source PACKAGE
    apt build-dep PACKAGE

For example

    apt source lilypond
    apt build-dep lilypond

## Fix the package

See [[hurd/porting/guidelines]] for help on fixing the package.

Notes: 

* char path[4096] is evil. Use dynamic allocation (if you can).
* use stuff like if (x < sysconf(_SC_PATH_MAX)) {}
* if need be, make it conditional

\#ifdef PATH_MAX
old, POSIX-violating code
\#else
GNU, better code
\#endif

## Test the fix (compile, run tests)

    cd PACKAGE
    dpkg-buildpackage -B

Also check the packages README for instructions.

## Submit the fix

See [[hurd/running/debian/patch_submission]].