Go compilation error

Playbook ID: go-compile-error Category: build Severity: high Tags: go, golang, compile, build, undefined

What this failure means

The Go compiler rejected the package because of a semantic error — undefined identifier, type mismatch, unused import, or interface non-compliance. The binary cannot be produced until the errors are resolved.

Common log signals

imported and not used
declared and not used
does not implement
undefined: 
cannot use 
too many arguments in call to
not enough arguments in call to
cannot assign to

Diagnosis

The Go compiler emitted one or more hard errors and aborted the build. These are always deterministic: the source must be corrected before go build ./... can succeed.

Common error classes:

• undefined: — a symbol, function, or type is referenced but not declared in the current package or any imported package.
• cannot use X as Y — a value of one type is passed where a different type is required, and no implicit conversion exists.
• imported and not used — a package was imported but none of its exported names appear in the file.
• declared and not used — a local variable was declared but never read.
• does not implement — a concrete type is used where an interface is expected but is missing one or more methods.

Fix steps

1. Run go build ./... locally to see the full diagnostic output:

   go build ./... 2>&1 | head -30
   

2. For undefined: Foo: import the package that defines Foo or move the declaration into scope.

3. For cannot use x (variable of type A) as type B: correct the type or add an explicit conversion where the semantics are safe.

4. For imported and not used: remove the unused import, or add a blank import _ "pkg" if the side-effect is intentional.

5. For declared and not used: use the variable or replace it with _.

6. For does not implement: add the missing method to the concrete type, or use the correct type that already satisfies the interface.

Validation

• Run go build ./... locally and confirm zero errors.
• Run go vet ./... to catch additional semantic issues before CI.
• Confirm the CI build step exits zero.

Likely files to inspect

• **/*.go
• go.mod

Run Faultline

faultline analyze build.log
faultline explain go-compile-error
faultline workflow build.log --json --mode agent

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Generated from playbooks/bundled/log/build/go-compile-error.yaml. Do not edit directly — run make docs-generate.