nektos/act · error

Cannot process container options: '%s': '%w'

Error message

Cannot process container options: '%s': '%w'

What it means

After flag parsing, mergeContainerConfigs calls parse(flags, copts, runtime.GOOS) to convert the parsed flags into container.Config/HostConfig (the same conversion docker CLI does). Any option whose value fails that conversion — invalid device spec, bad security-opt, malformed ulimit, bad PID mode, etc. — surfaces as 'Cannot process container options' wrapping the underlying error.

Source

Thrown at pkg/container/docker_run.go:384

	optionsArgs, err := shellquote.Split(input.Options)
	if err != nil {
		return nil, nil, fmt.Errorf("Cannot split container options: '%s': '%w'", input.Options, err)
	}

	err = flags.Parse(optionsArgs)
	if err != nil {
		return nil, nil, fmt.Errorf("Cannot parse container options: '%s': '%w'", input.Options, err)
	}

	if len(copts.netMode.Value()) == 0 {
		if err = copts.netMode.Set(cr.input.NetworkMode); err != nil {
			return nil, nil, fmt.Errorf("Cannot parse networkmode=%s. This is an internal error and should not happen: '%w'", cr.input.NetworkMode, err)
		}
	}

	containerConfig, err := parse(flags, copts, runtime.GOOS)
	if err != nil {
		return nil, nil, fmt.Errorf("Cannot process container options: '%s': '%w'", input.Options, err)
	}

	logger.Debugf("Custom container.Config from options ==> %+v", containerConfig.Config)

	err = mergo.Merge(config, containerConfig.Config, mergo.WithOverride)
	if err != nil {
		return nil, nil, fmt.Errorf("Cannot merge container.Config options: '%s': '%w'", input.Options, err)
	}
	logger.Debugf("Merged container.Config ==> %+v", config)

	logger.Debugf("Custom container.HostConfig from options ==> %+v", containerConfig.HostConfig)

	hostConfig.Binds = append(hostConfig.Binds, containerConfig.HostConfig.Binds...)
	hostConfig.Mounts = append(hostConfig.Mounts, containerConfig.HostConfig.Mounts...)
	binds := hostConfig.Binds
	mounts := hostConfig.Mounts
	err = mergo.Merge(hostConfig, containerConfig.HostConfig, mergo.WithOverride)
	if err != nil {

View on GitHub (pinned to 4f41128141)

Solutions

1. Read the wrapped error — it names the specific option that failed conversion
2. Fix that single option per its own validation rules (device rwm modes, ulimit name=soft:hard, seccomp path with valid JSON)
3. Test the option directly: docker run --rm <option> alpine true
4. Remove options you do not actually need in CI

Example fix

# before
options: --ulimit 65535

# after
options: --ulimit nofile=65535:65535

# shell: exercise each option exactly as the daemon will see it
for opt in $OPTIONS; do :; done
docker run --rm $OPTIONS alpine true

When it happens

Trigger: An option that tokenizes and parses as a flag but fails validation during conversion: --device with 4 segments, --security-opt seccomp=bad-json-path, --ulimit with wrong syntax, --pid=nonexistent, invalid shm/mount specs.

Common situations: Options copied from docker run that pass superficial parsing but are rejected by deep validation; platform-specific values (Windows-style paths on Linux) inside otherwise valid flags.

Related errors

• invalid storage option
• valid streams are STDIN, STDOUT and STDERR
• %s is not a valid mac address
• invalid logging opts for driver %s
• --pid: invalid PID mode

AI-assisted analysis of nektos/act@4f41128141 (2026-08-15). Data as JSON: /api/errors/854a091020bb6ab7. Report an issue: GitHub.