return true
	}
	if ctxt.GOOS == "illumos" && name == "solaris" {
		return true
	}
	if ctxt.GOOS == "ios" && name == "darwin" {
		return true
	}
	if name == "unix" && unixOS[ctxt.GOOS] {
		return true
	}
	if name == "boringcrypto" {
		name = "goexperiment.boringcrypto" // boringcrypto is an old name for goexperiment.boringcrypto
	}

	// other tags

				// content.  Similarly, atime is set whenever
				// the contents are accessed; also, it is set
				// whenever mtime is set.
			case "windows":
				t.Error(errormsg)
			default: // unix's
				if got, want := at0, tt.wantATime; !got.Equal(want) {
					mounts, err := ReadFile("/bin/mounts")
					if err != nil {
						mounts, err = ReadFile("/etc/mtab")
					}