E0428: Context processors that need each other

A package that reads a processor's variables by name is compiled after the processor's package, so the variables' types are known. Here that order can't be kept: the processor's package needs the package compiled first, through the variables another package reads by name. The message names the package, the processor and the packages between them; it is reported at the processor's entry in web.ContextProcessors(…). Reported by the compiler.

A processor's own imports never read its variables by name — that would be an import cycle — and they don't get them: a package nav.Context's package imports can't use badges, while the pages can.

Wrong

// main.go
web.ContextProcessors(orders.Context, users.Context)

// orders/context.go imports reports; reports/totals.vuka reads me
//   (users.Context's)
// users/context.go imports views; views/header.vuka reads cart
//   (orders.Context's)

views waits for orders, which imports reports, which waits for users, which imports views.

Right

// users/context.go imports what it needed of views from a package
// that reads no processor variable by name: users/model, say

A processor's package should import models and services, not the packages that render. See context processors.