nektos/act · error

--health-retries cannot be negative

Error message

--health-retries cannot be negative

What it means

Error [88]: The step's command inside the container exited with code 127 — the shell's 'command not found' code. Act maps it explicitly and links nektos/act#107 because it almost always means the image lacks /bin/bash (or the requested shell) and steps fail on every 'shell: bash' run. This is not a Docker API error; it is the job command failing in-image.

Source

Thrown at pkg/container/docker_cli.go:592

		copts.healthStartInterval != 0
	if copts.noHealthcheck {
		if haveHealthSettings {
			return nil, errors.New("--no-healthcheck conflicts with --health-* options")
		}
		healthConfig = &container.HealthConfig{Test: []string{"NONE"}}
	} else if haveHealthSettings {
		var probe []string
		if copts.healthCmd != "" {
			probe = []string{"CMD-SHELL", copts.healthCmd}
		}
		if copts.healthInterval < 0 {
			return nil, errors.New("--health-interval cannot be negative")
		}
		if copts.healthTimeout < 0 {
			return nil, errors.New("--health-timeout cannot be negative")
		}
		if copts.healthRetries < 0 {
			return nil, errors.New("--health-retries cannot be negative")
		}
		if copts.healthStartPeriod < 0 {
			return nil, errors.New("--health-start-period cannot be negative")
		}
		if copts.healthStartInterval < 0 {
			return nil, errors.New("--health-start-interval cannot be negative")
		}

		healthConfig = &container.HealthConfig{
			Test:          probe,
			Interval:      copts.healthInterval,
			Timeout:       copts.healthTimeout,
			StartPeriod:   copts.healthStartPeriod,
			StartInterval: copts.healthStartInterval,
			Retries:       copts.healthRetries,
		}
	}

View on GitHub (pinned to 4f41128141)

Solutions

1. Install bash in the image or switch the image to one with bash (debian/ubuntu based)
2. Set the step shell explicitly: shell: sh (or ash) for alpine images
3. Use 'runs-on: ubuntu-latest' (act maps to its default images with bash) for bash-dependent steps
4. For local actions, make entrypoint scripts POSIX sh compatible

Example fix

# before
jobs:
  build:
    runs-on: ubuntu-latest
    container: alpine:latest
    steps:
      - run: echo hi   # defaults to bash
# after
    steps:
      - run: echo hi
        shell: sh

// Choose shell per image family before running
func shellFor(image string) string {
	if strings.Contains(image, "alpine") || strings.Contains(image, "busybox") {
		return "sh"
	}
	return "bash"
}

func imageHasBash(image string) bool {
	// check via docker if scripting
	out, err := exec.Command("docker", "run", "--rm", image, "sh", "-c", "command -v bash").Output()
	return err == nil && len(out) > 0
}

if err := step(ctx); err != nil && strings.Contains(err.Error(), "exitcode '127'") {
	// set shell: sh on the step and re-run
}

When it happens

Trigger: A workflow step uses shell: bash (act's default for run:) in an image without bash (alpine, distroless, scratch); the entrypoint script references a missing binary; a local action's entrypoint uses bash while the job container is alpine.

Common situations: Default act images aside, using runs-on container images like alpine where only sh/ash exist; distroless images; images where bash is not on PATH; scripts with a #!/bin/bash shebang run via 'sh -c'.

Related errors

• --health-timeout cannot be negative
• --health-start-period cannot be negative
• conflicting options: cannot specify both --link-local-ip and
• --pid: invalid PID mode
• --uts: invalid UTS mode

AI-assisted analysis of nektos/act@4f41128141 (2026-08-15). Data as JSON: /api/errors/a6a24aa3e6533392. Report an issue: GitHub.