Single-Shot Mode¶

Run rninja without using the daemon process.

Overview¶

Single-shot mode (--no-daemon) runs builds directly without connecting to or spawning a daemon.

rninja --no-daemon

When to Use¶

Containers and Ephemeral Environments¶

In Docker or short-lived environments:

# Dockerfile
RUN rninja --no-daemon

Daemon provides no benefit when the environment is destroyed after the build.

Debugging Build Issues¶

When isolating problems:

# Remove daemon as a variable
rninja --no-daemon -d explain

CI Single-Job Runners¶

For CI jobs that run one build and exit:

# .github/workflows/build.yml
- run: rninja --no-daemon

Resource-Constrained Systems¶

When memory for daemon is not available:

# Embedded system or low-memory VM
rninja --no-daemon

Scripted Builds¶

For predictable, isolated execution:

#!/bin/bash
# build.sh - deterministic build script
rninja --no-daemon -j4

Usage¶

Basic¶

rninja --no-daemon

With Other Options¶

# Combine with any other flags
rninja --no-daemon -j8 -v my_target
rninja --no-daemon -C build/release
rninja --no-daemon -t clean

Environment Variable¶

# Always use single-shot mode
export RNINJA_NO_DAEMON=1
rninja  # Runs without daemon

Performance Comparison¶

Metric	With Daemon	Single-Shot
First build	~200ms + build	~200ms + build
Subsequent builds	~20ms + build	~200ms + build
Memory baseline	50-200 MB	0 (process exits)

When Daemon Helps¶

Multiple builds in same session
Interactive development
IDE integration

When Daemon Doesn't Help¶

Single builds (CI)
Isolated environments
Infrequent builds

Caching Still Works¶

Single-shot mode still uses the cache:

# First build - populates cache
rninja --no-daemon

# Second build - uses cache
rninja --no-daemon

The cache is independent of the daemon.

CI Configuration Examples¶

GitHub Actions¶

steps:
  - name: Build
    run: rninja --no-daemon

GitLab CI¶

build:
  script:
    - rninja --no-daemon

Docker Build¶

FROM rust:latest

COPY . /app
WORKDIR /app

# No daemon in container
RUN rninja --no-daemon

Makefile Integration¶

.PHONY: build
build:
    rninja --no-daemon

Comparison with Daemon Mode¶

Process Model¶

Daemon Mode:

[rninja CLI] → [daemon process] → [build execution]
     ↓              ↓
   exits        persists

Single-Shot Mode:

[rninja process] → [build execution]
         ↓
       exits

Resource Usage¶

Daemon Mode:

Daemon process always running
Consumes memory for cached state
Faster subsequent builds

Single-Shot Mode:

No persistent process
Memory freed after build
Consistent startup time

Troubleshooting¶

Build Slower in Single-Shot¶

Expected - daemon provides caching benefits:

# If startup time matters, use daemon
rninja  # Let daemon spawn

Cache Not Working¶

Cache should work in both modes:

# Check cache
rninja --no-daemon -t cache-stats

Want Daemon But Getting Single-Shot¶

Check for environment variables:

env | grep RNINJA_NO_DAEMON
unset RNINJA_NO_DAEMON

Best Practices¶

Use Single-Shot When:¶

Running in containers
CI single-job runners
Debugging
Scripts requiring predictability

Use Daemon When:¶

Interactive development
Multiple builds per session
IDE integration
Fast iteration cycles

Default Recommendation¶

Let rninja decide:

rninja  # Uses daemon if beneficial

Specify only when you have a specific need:

rninja --no-daemon  # When daemon is definitely not needed