How to Update an Existing Project¶

This guide covers updating a project that was generated with copier-py to incorporate template improvements.

Update to the latest template¶

Run copier update in your project directory:

cd /path/to/your-project
copier update --trust

Copier compares your project against the latest template version and applies changes. If there are conflicts between your modifications and template updates, copier presents a diff for you to resolve.

Update to a specific template version¶

To update to a specific tag or commit of the template:

copier update --trust --vcs-ref v1.2.0

Change configuration options¶

To change options you selected during initial generation (e.g., enable publishing, change the Sphinx theme):

copier update --trust

Copier re-prompts you for all configuration values, pre-filled with your previous answers. Change any values you want and copier regenerates the affected files.

Review changes before applying¶

To see what would change without applying:

copier update --trust --pretend

This performs a dry run and shows the diff.

Resolve conflicts¶

When copier detects conflicts between your changes and template updates:

Copier creates .rej files containing the rejected hunks
Review each .rej file and manually apply the intended changes
Delete the .rej files after resolving

Search for rejection files:

find . -name "*.rej"

Skip specific questions¶

If you want to keep specific answers unchanged and skip their prompts:

copier update --trust --defaults

This uses your previously saved answers (stored in .copier-answers.yml) without prompting.