Which factors influence migration checksums

[rster2002]

In one of my projects I split my code into multiple crates, but after I did that migrations wouldn't run as expected as the checksum seemed to have been changed. I'm not entirely sure why it has changed as the SQL code hasn't changed.

When I was restructuring I changed the following:

• Moved the migrations directory from the root of the project to a crate in a cargo workspace.
• Changed the version nr of the crate with the migrations.

My question is why did the checksum change and what factors influence the migration checksums so I can avoid accedentally changing them in the future.