Diagnostics

Goalchemy diagnostics have stable codes, severity, source location where available, symbol, feature, message, and a one-line remedy. Human and JSON output carry the same information.

Prefix	Category	Meaning
GCL	Loading	Package selection, parsing, typing, or source-profile failure.
GCS	Source subset	Go code is valid but exceeds the currently implemented language gate.
GCC	Contracts	A canonical or target contract is malformed or inconsistent.
GCI	Intermediate representation	Lowering or IR verification failed.
GCE	Emission	A target lacks a required operation, type representation, or runtime dependency.
GCT	Conformance	A generated program or runtime operation differs from its contract.
GCW	Warning	Code compiles and runs but likely does not do what it appears to; the build continues.

The initial checker reserves GCL001–GCL004 and GCS001–GCS010. Later phases allocate codes from the remaining categories when their corresponding checks exist. A diagnostic code’s meaning must not change silently between releases.

The source baseline is Go 1.25 on Linux amd64 with cgo disabled, checked using Go 1.27.1. The repository’s go.mod selects the reference toolchain. Source build tags are explicit checker inputs.