Spec-cleaner and rediff patch - New Helper Scripts for Maintainers

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Maintainers' work includes a lot of routine tasks — adoption of spec files to match evolving packaging policies and build tools, adoption of existing patches for new upstream versions, update of package file lists and so on. Some of such tasks are performed automatically by build tools — rpmbuild itself and auxilliary scripts from spec-helper package. However, these scripts by design can’t solve a lot of problems — in particular those that require modification of spec files.

To simplify maintainers' life a little more, we have included two new scripts to the spec-helper package. The scritps' names are self-explaining — spec-cleaner and rediff_patch. These scripts are not launched automatically during the build; they are intended to be used by maintainers manually. Update spec-helper package in your system and you will get these scripts in your /usr/bin.

Spec-cleaner performs the following actions:

  • removes obsolete declarations that makes no sense nowadays — for example, definitions of BuildRoot and Packager, requirement on install-info, buildroot cleanup and so on;
  • modifies formatting of macros and variables — according to our policies, variables in spec files should be emraced with braces — %{const}, while for macros braces should not be used — %{macro}. Note that spec-cleaner only reformats macros and variables known to it. If you have some entities defined by your own, the script will leave them «as is»;
  • formats Summary — capitalize the first letter and removes the dot from its end;
  • removes explicit declarations of %{name}, %{version} and %{release} variables;
  • replace obsolete macros with modern analogues;
  • … and performs a lot of other small tasks which will help to make spec files smaller and cleaner and avoid claiming from rpmlint.

When developing spec-cleaner, we try to avoid situations when the new spec-file becomes incorrect in some sense. Due to this reason, some spec-file issues that may seem to be easy to fix are not automatically fixed yet.

Meanwhile, old developers may notice that spec-cleaner is a modern and much powerful analogue of old macroszification script which was present in spec-helper for years. Now this script is dropped — use new spec-cleaner instead.

As for Rediff_patch, then you have likely guessed that it tries to rediff an existing patch against a new tarball with source code. Please read the instructions below carefully before trying to use this script:

  1. rediff_patch should be launched in the folder of a cloned Git project, where spec file and patches reside. Spec file is used to determine how the patch should be applied;
  2. the new tarball should be placed in the same folder;
  3. the script should be launched in the following way:
 rediff_patch <patch_ro_rediff> <tarball>

If you folder contains only one tarball, then you can omit second argument.

During its work, rediff_patch creates rediff_patch folder, unpacks tarball into it and tries to apply the patch to the unpacked content. To apply the patch, it uses parameters extracted from the spec file, but adds «--force» option and uses default system value for the «fuzz» option (remember that rpmbuild uses «--fuzz=0» by default). Currently the script only handles situation when tarball has a single top-lever folder; it will reject to work with tar bombs

If everything goes fine, then you will find a new patch (with the «.new» suffix) near the old one. rediff_patch folder with the whole content will be removed.

If something goes wrong (e.g., patch was applied only partially and some hunks failed) then you will be left with rediff_patch folder containing two subfolders — the original one and the new one, where a patch was tried to be applied So you will be able to analyze the reasons of failures and finish rediff manually.

As our practice shows, in reality most patches fail to rediff completely automatically, even with «--force» and more soft «--fuzz». But even rediff_patch managed to prepare a new patch for you, do not forget to check this patch carefully — '--force' sometimes leads to undesired results. But even if rediff_patch failed — well, at least we have saved some time, since it has unpacked tarball for us and performed a first attempt to apply the patch.

We hope that these two new scripts will make your life a little easier. Both scripts are easy to use and straightforward. As usual, comments, suggestions and patches are welcome.

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