When building, the CGO_CFLAGS, CGO_CPPFLAGS, CGO_CXXFLAGS, CGO_FFLAGS and
CGO_LDFLAGS environment variables are added to the flags derived from
these directives. Package-specific flags should be set using the
directives, not the environment variables, so that builds work in
unmodified environments. Flags obtained from environment variables
are not subject to the security limitations described above.

using newer toolchains to compile old code.

A GODEBUG setting is a `key=value` pair
that controls the execution of certain parts of a Go program.
The environment variable `GODEBUG`
can hold a comma-separated list of these settings.
For example, if a Go program is running in an environment that contains

	GODEBUG=http2client=0,http2server=0

then that Go program will disable the use of HTTP/2 by default in both

in GOROOT/src.

Maintaining vendor directories
==============================

Before updating vendor directories, ensure that module mode is enabled.
Make sure that GO111MODULE is not set in the environment, or that it is
set to 'on' or 'auto', and if you use a go.work file, set GOWORK=off.

Requirements may be added, updated, and removed with 'go get'.
The vendor directory may be updated with 'go mod vendor'.

## Tools {#tools}

### Go command {#go-command}

Setting the `GOROOT_FINAL` environment variable no longer has an effect
([#62047](https://go.dev/issue/62047)).
Distributions that install the `go` command to a location other than
`$GOROOT/bin/go` should install a symlink instead of relocating
or copying the `go` binary.

### Vet {#vet}

The `go vet` subcommand now includes the

</li>

</ul>

<p>
The value of <code>GOMIPS</code> environment variable (<code>hardfloat</code> or
<code>softfloat</code>) is made available to assembly code by predefining either
<code>GOMIPS_hardfloat</code> or <code>GOMIPS_softfloat</code>.
</p>

<p>
The value of <code>GOMIPS64</code> environment variable (<code>hardfloat</code> or

<i>packages</i>, whose properties allow efficient management of
dependencies.
</p>

<p>
The grammar is compact and simple to parse, allowing for easy analysis
by automatic tools such as integrated development environments.
</p>

<h2 id="Notation">Notation</h2>
<p>
The syntax is specified using Extended Backus-Naur Form (EBNF):
</p>

<pre class="grammar">
Production  = production_name "=" [ Expression ] "." .

//
// Since the set of packages that exist depends on context, the result of
// loadImports also depends on context. However, to improve test running time
// the configuration for each environment is cached across runs.
func (w *Walker) loadImports() {
	if w.context == nil {
		return // test-only Walker; does not use the import map
	}

	name := contextName(w.context)

// Any remaining data in the current file is automatically discarded.
// At the end of the archive, Next returns the error io.EOF.
//
// If Next encounters a non-local name (as defined by [filepath.IsLocal])
// and the GODEBUG environment variable contains `tarinsecurepath=0`,
// Next returns the header with an [ErrInsecurePath] error.
// A future version of Go may introduce this behavior by default.
// Programs that want to accept non-local names can ignore

	BINV	$63, X6					// 1313f36b
	BINVI	$1, X7, X8				// 13941368
	BSET	X8, X9, X10				// 33958428
	BSET	$63, X9					// 9394f42b
	BSETI	$1, X10, X11				// 93151528

	// Privileged ISA

	// 3.2.1: Environment Call and Breakpoint
	ECALL						// 73000000
	SCALL						// 73000000
	EBREAK						// 73001000
	SBREAK						// 73001000

	// Arbitrary bytes (entered in little-endian mode)

<i>packages</i>, whose properties allow efficient management of
dependencies.
</p>

<p>
The syntax is compact and simple to parse, allowing for easy analysis
by automatic tools such as integrated development environments.
</p>

<h2 id="Notation">Notation</h2>
<p>
The syntax is specified using a
<a href="https://en.wikipedia.org/wiki/Wirth_syntax_notation">variant</a>
of Extended Backus-Naur Form (EBNF):
</p>