MGS1104: this program does not link the Buzz engine

A Go program asked the magus library to evaluate a magusfile, and the program was built without the Buzz engine that evaluates one. The load stops there.

[MGS1104] cannot evaluate /repo/magusfile.buzz: this program does not link the
Buzz engine; add the blank import _ "github.com/egladman/magus/buzzengine" to
its main package

The magus command links the engine, so this only reaches a program that imports github.com/egladman/magus as a library.

Why

The library does not link the engine on its own, so a program that never evaluates a magusfile does not carry the Buzz VM.

The alternative to failing is silence. A workspace loaded without its magusfiles has no custom targets, no magus.project() settings and no per-target policy, and it renders exactly like a workspace that declares none. Only one of those is true, and nothing in the result says which.

So the load returns *types.EngineNotLinkedError instead of a partial workspace. A workspace with no magusfile still opens without the engine.

Fix

Link the engine from the program's main package:

import _ "github.com/egladman/magus/buzzengine"

Match the error from Go with errors.As:

var notLinked *types.EngineNotLinkedError
if errors.As(err, &notLinked) {
    // the program was built without buzzengine
}

See also

• Go SDK: what the library does and does not link.
• MGS1101: a capability reported as unavailable, never as empty.