anomalyco/sst · error

failed to install dependencies: %w

Error message

failed to install dependencies: %w

What it means

installDependenciesForBuild delegates actual dependency installation to installDependenciesForLambda (pip install of requirements for the target Lambda architecture). Any failure inside that pipeline — pip invocation, container build, copying source or synced deps — is surfaced here as 'failed to install dependencies'.

Source

Thrown at pkg/runtime/python/build.go:565

func installDependenciesForBuild(ctx context.Context, input *runtime.BuildInput, projectInfo *projectInfo) error {
	if err := os.MkdirAll(input.Out(), 0755); err != nil {
		return fmt.Errorf("failed to create output directory: %w", err)
	}

	requirementsFile := filepath.Join(input.Out(), "requirements.txt")
	if err := generateOrCopyRequirementsFile(ctx, projectInfo, requirementsFile); err != nil {
		return fmt.Errorf("failed to generate requirements file: %w", err)
	}

	// Determine architecture for Lambda
	architecture := "x86_64"
	if props, err := parseInputProperties(input); err == nil && props.Architecture != "" {
		architecture = props.Architecture
	}

	// Install dependencies for the target platform (Linux)
	if err := installDependenciesForLambda(ctx, input, projectInfo, architecture); err != nil {
		return fmt.Errorf("failed to install dependencies: %w", err)
	}

	return nil
}

// generateOrCopyRequirementsFile generates requirements.txt once per workspace,
// then copies it to each function's output directory.
func generateOrCopyRequirementsFile(ctx context.Context, projectInfo *projectInfo, outputFile string) error {
	// Include dev dependencies for projects without a build system (source-only projects).
	// If the project has no [build-system], runtime deps may be in the dev group.
	noDev := true
	if projectInfo.PyprojectPath != "" {
		if !hasBuildConfig(filepath.Dir(projectInfo.PyprojectPath)) {
			noDev = false
		}
	}

	// Determine if this is a workspace member (has its own pyproject.toml in a subdirectory)

View on GitHub (pinned to a0bd20f762)

Solutions

1. Ensure python3 and pip (matching the runtime version) are on PATH: `python3 --version && python3 -m pip --version`
2. Run `pip install -r <output>/requirements.txt --platform manylinux2014_x86_64 --target /tmp/test` locally to see the real resolve failure
3. For container builds, verify Docker is installed and the daemon is running (docker info)
4. Read the wrapped inner error and the pip output above it in the logs for the specific package/network failure

Example fix

// before: pip resolves with local platform, failing on macOS for x86_64 Lambda
// after: reproduce install exactly as the build does
python3 -m pip install -r requirements.txt \
  --platform manylinux2014_x86_64 --only-binary=:all: --target /tmp/lambda-test

if _, err := exec.LookPath("python3"); err != nil { log.Fatal("python3 not on PATH") }
if _, err := exec.LookPath("docker"); err != nil && containerBuild { log.Fatal("docker required for container builds") }
// pre-resolve deps the way the build does:
// python3 -m pip install -r requirements.txt --platform manylinux2014_x86_64 --only-binary=:all: --target /tmp/probe

err := deploy()
if err != nil && strings.Contains(err.Error(), "failed to install dependencies") {
	// read the wrapped pip/docker error above this line in logs;
	// common causes: no toolchain, PyPI blocked, docker daemon down
	if errors.Is(err, dockerNotRunning) { startDockerDaemon() }
	os.Exit(1)
}

When it happens

Trigger: installDependenciesForLambda returns an error: python3/pip not found or wrong version in PATH, pip resolve failure from bad requirements, Docker unavailable for container builds, or any copySourceFilesSimple/copySyncedDependencies failure.

Common situations: No Python toolchain on the CI runner or a Python 2 'python' binary in PATH; requirements.txt pins a package/version that doesn't exist for the target architecture; Docker daemon not running for container-based builds; corporate proxy blocking PyPI.

Related errors

• failed to copy synced dependencies: %w
• failed to generate requirements file: %w
• failed to filter requirements: %w
• failed to run uv pip install: %v %s Function: %s Handler: %
• failed to copy dependencies to artifact: %w

AI-assisted analysis of anomalyco/sst@a0bd20f762 (2026-08-30). Data as JSON: /api/errors/dd021275c79cad1e. Report an issue: GitHub.