CustomParseCmdAndArgs 因为关闭了 cobra 的解析功能，需要手动构造并解析 goc flags.

NewBuild creates a Build struct.

TmpFolderName generates a directory name according to the path.

Build struct a build.

FileVar holds the name of the generated coverage variables targeting the named file.

ModuleError represents the error loading module.

ModulePublic represents the package info of a module.

Package map a package output by go list this is subset of package struct in: https://github.com/golang/go/blob/master/src/cmd/go/internal/load/pkg.go#L58.

PackageCover holds all the generate coverage variables of a package.

PackageError is the error info for a package when list failed.