// Do returns the value returned by the one call to f.
func (c *Cache[K, V]) Do(key K, f func() V) V {
	entryIface, ok := c.m.Load(key)
	if !ok {
		entryIface, _ = c.m.LoadOrStore(key, new(cacheEntry[V]))
	}
	e := entryIface.(*cacheEntry[V])
	if !e.done.Load() {
		e.mu.Lock()
		if !e.done.Load() {
			e.result = f()
			e.done.Store(true)
		}
		e.mu.Unlock()
	}
	return e.result
}

support lazy module loading.)

The -compat flag preserves any additional checksums needed for the
'go' command from the indicated major Go release to successfully load
the module graph, and causes tidy to error out if that version of the
'go' command would load any imported package from a different module
version. By default, tidy acts as if the -compat flag were set to the
version prior to the one indicated by the 'go' directive in the go.mod

// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package load

import (
	"errors"
	"fmt"
	"go/build"
	"internal/godebugs"
	"sort"
	"strconv"
	"strings"

	"cmd/go/internal/gover"
	"cmd/go/internal/modload"
)

var ErrNotGoDebug = errors.New("not //go:debug line")