go-clean

Print the remove commands instead of actually removing anything

$ go clean -n

$ go clean -cache

$ go clean -testcache

$ go clean -modcache

go clean [flags] [packages]
Removes object files and cached build artifacts from Go workspaces.

-i
    Removes the corresponding installed archive or binary created by go install.

-n
    Prints the commands that go clean would execute, but does not run them.

-x
    Prints the commands that go clean executes as it runs.

-cache
    Removes the entire Go build cache, located at GOCACHE. This can significantly free up disk space but may slow down subsequent builds as everything needs to be recompiled.

-testcache
    Expires all test results in the Go build cache. Subsequent go test commands will re-run tests.

-modcache
    Removes the entire Go module download cache, located at GOMODCACHE. This forces modules to be re-downloaded upon demand.

-fuzzcache
    Removes the entire Go fuzzing cache, located at GOFUZZCACHE. (Introduced in Go 1.18).

go clean is a crucial command within the Go programming language toolchain, designed to remove object files, executable binaries, and cached test results from a Go workspace. Its primary purpose is to help developers manage disk space, ensure fresh builds by clearing potentially stale or corrupted artifacts, and troubleshoot build issues. By default, it operates on the current module or specified packages, deleting files created by go build, go install, and go test -c. The command can also target the global Go build cache (GOCACHE), module download cache (GOMODCACHE), and fuzzing cache (GOFUZZCACHE), providing a comprehensive way to reset the build environment. This flexibility makes go clean an essential utility for maintaining a clean and efficient Go development workflow.

• go clean only removes files specifically created by the Go toolchain (go build, go install, go test -c). It does not clean up arbitrary project output directories or files not managed by Go.
• Using flags like -cache or -modcache can delete a substantial amount of data. While this frees disk space, it will cause subsequent builds and module resolutions to be slower as they must re-download or rebuild everything.
• The command operates on the current working directory and its subdirectories by default, or on specified packages. Be mindful of the context when executing go clean.

The behavior of go clean is influenced by several environment variables that define the locations of caches it manages:
GOCACHE: Specifies the location of the Go build cache.
GOMODCACHE: Specifies the location of the Go module download cache.
GOFUZZCACHE: Specifies the location of the Go fuzzing cache.

go clean is typically used for:
1. Freeing up disk space by removing compiled binaries and caches.
2. Ensuring a fresh build by clearing stale artifacts before recompilation.
3. Troubleshooting build or dependency resolution issues that might be caused by corrupted cache entries.

go clean has been an integral part of the Go programming language toolchain since its inception, serving as a fundamental utility for managing build artifacts. As Go evolved, particularly with the introduction of the build cache in Go 1.8 and modules in Go 1.11, the command gained new functionalities to manage these additions. Flags like -cache and -modcache were introduced to specifically clear these new caching mechanisms, adapting go clean to the changing landscape of Go's dependency management and build optimization. The -fuzzcache flag was added in Go 1.18 to support the new fuzzing capabilities. Its core function of removing object files remains consistent, evolving to address new challenges in the Go ecosystem.

go build(1), go install(1), go test(1), go get(1)