Package reset halted due to encountering local changes

[evgeny-barinov]

From time to time I catch this error while installing composer packages. So what can be a possible reason of this happening? Thanks!

[Vaimo\ComposerPatches\Exceptions\PackageResetException]
Package reset halted due to encountering local changes

[allanpaiste]

This was included to avoid situations that could lead to uncommitted changes to be wiped when patch commands are used (note that the patch applier logic also triggers when a install/update event targets either directly or indirectly a package that has patches defined against it).

The way the patches are applied is based on the standard Composer behaviour of reinstalling a package which would mean that a user can potentially lose changes that they have made to the sub-components and their project, so this error/check has been put in place to avoid such unfortunate situations BUT it could also be caused by the dev-versioned package being targeted by some patch (in which case it'd be actually OK to reinstall it -- but there's no sophisticated logic behind the whole check to differentiate between the two situations).

You can force the reset in all such cases by using --force flag while using composer patch:<apply/redo/undo>.

If you'd want this to be the default behaviour on every composer event that includes patches, you can also add the following to your project's package.json:

{
  "extra": {
    "patcher": {
      "force-reset": true
    }
  }
}

[allanpaiste]

One thing that could be done here would be to track the fingerprint of the whole code-base of the patched package to determine if changes introduced are from the patches.

Another thing that should be checked for is to see if there's a probability for a situation to occur where there are two patches against one dev-version package where first one introduces the code modifications and second one fails.