(Older toolchains ignore `//go:debug` directives entirely.)

The defaults that will be compiled into a main package
are reported by the command:

{{raw `
	go list -f '{{.DefaultGODEBUG}}' my/main/package
`}}

Only differences from the base Go toolchain defaults are reported.

When testing a package, `//go:debug` lines in the `*_test.go`
files are treated as directives for the test's main package.

On Windows, the mode bits reported by [Lstat] and [Stat] for
reparse points changed. Mount points no longer have [ModeSymlink] set,
and reparse points that are not symlinks, Unix sockets, or dedup files
now always have [ModeIrregular] set.
This behavior is controlled by the `winsymlink` setting.
For Go 1.23, it defaults to `winsymlink=1`.

Use caution when passing '-u' to 'go get'. The '-u' flag updates
modules providing all transitively imported packages, not only
the module providing the target package.

Note that 'go mod vendor' only copies packages that are transitively
imported by packages in the current module. If a new package is needed,