[e1g]

Especially when unions are involved. We have a flexible schema for many parameters (e.g., X accepts an object or an array of them, and one object has some properties that could be an enum or a detailed shape), and both Zod and Valibot produce incomprehensible and useless error messages that don’t explain what’s wrong. We had to roll our own.

[alganet]

Have you tried applying boolean algebra conversions on the schema? Some ORs can be written as NOT AND expressions. I don't know about these JS versions, but in my lib the choice of boolean expression had influence on th3 error output.