abiosoft/colima · warning

unable to enable rosetta: %w

Error message

unable to enable rosetta: %w

What it means

On macOS Virtualization Framework with Rosetta enabled, Colima registers the Rosetta binfmt handler in the guest by echoing a magic/mask registration line into /proc/sys/fs/binfmt_misc/register (guarded by a stat so it is idempotent). On failure it only warns and returns nil, so start proceeds; x86_64 binaries on Apple Silicon will then fall back to slower qemu emulation or fail to run.

Source

Thrown at environment/vm/lima/lima.go:325

	// registry certs
	a.Add(l.copyCerts)

	// cross-platform emulation
	a.Add(func() error {
		// use binfmt when emulation is disabled i.e. host arch
		if conf.Binfmt != nil && *conf.Binfmt {
			if arch := environment.HostArch(); arch == environment.Arch(conf.Arch).Value() {
				if err := core.SetupBinfmt(l.host, l, environment.Arch(conf.Arch)); err != nil {
					logrus.Warn(fmt.Errorf("unable to enable qemu %s emulation: %w", arch, err))
				}
			}
		}

		if l.limaConf.VMOpts.VZOpts.Rosetta.Enabled {
			// enable rosetta
			err := l.Run("sudo", "sh", "-c", `stat /proc/sys/fs/binfmt_misc/rosetta || echo ':rosetta:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x3e\x00:\xff\xff\xff\xff\xff\xfe\xfe\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/mnt/lima-rosetta/rosetta:OCF' > /proc/sys/fs/binfmt_misc/register`)
			if err != nil {
				logrus.Warn(fmt.Errorf("unable to enable rosetta: %w", err))
				return nil
			}

			// disable qemu
			if err := l.RunQuiet("stat", "/proc/sys/fs/binfmt_misc/qemu-x86_64"); err == nil {
				err = l.Run("sudo", "sh", "-c", `echo 0 > /proc/sys/fs/binfmt_misc/qemu-x86_64`)
				if err != nil {
					logrus.Warn(fmt.Errorf("unable to disable qemu x86_84 emulation: %w", err))
				}
			}
		}

		return nil
	})

	// replicate addresses when network address is disabled
	a.Add(func() error {
		if err := l.replicateHostAddresses(conf); err != nil {

View on GitHub (pinned to c3a5f9184d)

Solutions

1. Ensure prerequisites: macOS host, VZ driver (`--vm-type vz`), Rosetta support enabled, and the official image that mounts /mnt/lima-rosetta.
2. If Rosetta is not required, disable it (`--vz-rosetta=false`) to silence the warning and rely on qemu.
3. Verify inside the guest: `colima ssh -- ls /proc/sys/fs/binfmt_misc /mnt/lima-rosetta/rosetta`.
4. Update macOS/Colima; older VZ stacks had Rosetta issues resolved in later releases.

Example fix

# before
colima start --vm-type vz --vz-rosetta   # warns: unable to enable rosetta

# after (if Rosetta not needed)
colima start --vm-type vz --vz-rosetta=false

Non-fatal (warn + return nil). If foreign-arch binaries are slow/failing afterwards, fall back to qemu by disabling Rosetta (--vz-rosetta=false).

When it happens

Trigger: VZ driver + rosetta enabled (`colima start --vz-rosetta` / config rosetta) on guests where binfmt_misc is unavailable or read-only, on Linux hosts (Rosetta is macOS-only and requires /mnt/lima-rosetta sharing), or when the rosetta binary mount is missing in the guest.

Common situations: Apple Silicon users with VZ+Rosetta on custom images lacking the rosetta mount; kernel/security settings blocking binfmt registration; expecting Rosetta on Linux hosts where it cannot work.

Related errors

• unable to disable qemu x86_84 emulation: %w
• unable to enable qemu %s emulation: %w
• unable to resize disk: %w
• error retrieving current runtime: empty value
• runtime cannot be updated, %s is not running

AI-assisted analysis of abiosoft/colima@c3a5f9184d (2026-08-15). Data as JSON: /api/errors/e044f6d17f0187dd. Report an issue: GitHub.