| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| os/exec | Package exec runs external commands. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |