gohugoio/hugo · error

cannot use --renderToMemory with --destination

Error message

cannot use --renderToMemory with --destination

What it means

Hugo's `hugo server` command validates its flag combination during PreRun. `--renderToMemory` serves the rendered site from an in-memory filesystem, so writing to a disk destination is contradictory; if the `--destination` flag was explicitly changed while `renderToMemory` is set, Hugo fails fast rather than silently ignoring one of them.

Source

Thrown at commands/server.go:603

			if err := c.setServerInfoInConfig(); err != nil {
				return err
			}

			if !reloaded && c.fastRenderMode {
				c.withConf(func(conf *commonConfig) {
					conf.fs.PublishDir = hugofs.NewHashingFs(conf.fs.PublishDir, c.changeDetector)
					conf.fs.PublishDirStatic = hugofs.NewHashingFs(conf.fs.PublishDirStatic, c.changeDetector)
				})
			}

			return nil
		},
	)

	destinationFlag := cd.CobraCommand.Flags().Lookup("destination")
	if c.r.renderToMemory && (destinationFlag != nil && destinationFlag.Changed) {
		return fmt.Errorf("cannot use --renderToMemory with --destination")
	}
	c.doLiveReload = !c.disableLiveReload
	c.fastRenderMode = !c.disableFastRender
	c.showErrorInBrowser = c.doLiveReload && !c.disableBrowserError

	if c.fastRenderMode {
		// For now, fast render mode only. It should, however, be fast enough
		// for the full variant, too.
		c.changeDetector = &fileChangeDetector{
			// We use this detector to decide to do a Hot reload of a single path or not.
			// We need to filter out source maps and possibly some other to be able
			// to make that decision.
			irrelevantRe: regexp.MustCompile(`\.map$`),
		}

		c.changeDetector.PrepareNew()

	}

View on GitHub ↗ (pinned to 8a468df065)

Solutions

1. Drop `--destination`/`-d` when using `--renderToMemory` — the memory filesystem serves the site directly.
2. If you need output on disk (e.g. for another tool to read), drop `--renderToMemory` instead.
3. Check shell aliases, Makefiles, and npm scripts for a hardcoded `-d` flag.

Example fix

# before
hugo server --renderToMemory -d public
# after
hugo server --renderToMemory

// before invoking hugo server
if flags.RenderToMemory && flags.Destination != "" {
    return errors.New("choose either --renderToMemory or --destination, not both")
}

When it happens

Trigger: Running `hugo server --renderToMemory --destination <dir>` (or with `-d`). The check fires only when the cobra `destination` flag is marked Changed, i.e. explicitly passed on the command line while `c.r.renderToMemory` is true.

Common situations: Copy-pasting a build command (`hugo -d public`) and adding `server --renderToMemory` for live preview; CI scripts or Makefiles that always append `--destination`; shell aliases that bake in `-d` and later add `--renderToMemory` for speed.

Related errors

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• --appendPort=false not supported when in multihost mode
• failed to parse root certificate
• failed to parse certificate PEM
• failed to parse certificate: %v

AI-assisted analysis of gohugoio/hugo@8a468df065 (2026-07-31). Data as JSON: /data/errors/74f4009852cbf794.json. Report an issue: GitHub ↗.