DDEV for Drupal Development

Comprehensive patterns for using DDEV as your local Drupal development environment, including setup, configuration, workflow optimization, and troubleshooting.

When This Skill Activates

Activates when working with DDEV local development including:

• DDEV configuration (.ddev/config.yaml)
• Local environment setup and management
• Database import/export operations
• Drush integration
• Xdebug and debugging tools
• Performance optimization
• Multi-site and custom commands

Available Topics

Core Setup

• @references/config-yaml.md - .ddev/config.yaml reference
• @references/workflows.md - New/imported project setup, remote DB sync, daily workflow, multi-project management

Database Operations

• @references/database.md - Import, export, and snapshot workflows

Development Tools

• @references/xdebug.md - Debugging with Xdebug
• @references/solr.md - Local Solr search setup

Advanced

• @references/custom-commands.md - Creating project-specific commands
• @references/performance.md - Optimizing DDEV performance
• @references/load-and-recovery.md - Host CPU saturation, post-crash recovery traps, trimming the Mutagen payload, Kernel tests on a throwaway DB, coordinating multiple agents on one project

See /references/ directory for complete documentation.

References

Read the matching file when the task needs that detail; the Common Issues section below stays here because it is needed on almost every use.

Quick Reference

Essential Commands

# Start project
ddev start

# Stop project
ddev stop

# Restart services
ddev restart

# SSH into web container
ddev ssh

# Run Drush commands
ddev drush cr
ddev drush status
ddev drush config:status

# Run Composer
ddev composer require drupal/module_name
ddev composer update

# Database operations
ddev import-db --file=backup.sql.gz
ddev export-db --file=backup.sql.gz
ddev snapshot

# View logs
ddev logs
ddev logs -f    # Follow mode

# Describe project
ddev describe

# Access URLs
ddev launch     # Open site in browser

Basic .ddev/config.yaml

name: myproject
type: drupal11
docroot: web
php_version: "8.3"
webserver_type: nginx-fpm
database:
  type: mariadb
  version: "10.6"
nodejs_version: "24"

# Additional services
additional_services:
  - solr

# Custom upload/execution limits
upload_dirs:
  - web/sites/default/files

# Performance settings
performance_mode: mutagen  # For macOS

Best Practices

1. Commit .ddev/config.yaml - Share config with team
2. Use ddev composer instead of local composer
3. Don't commit database snapshots - Too large
4. Create snapshots before risky operations
5. Disable Xdebug when not debugging - Performance impact
6. Use mutagen on macOS - Much faster file sync
7. Regular ddev poweroff - Free up system resources
8. Version pin services - PHP, database, Node.js
9. Use hooks for automation - Post-start tasks
10. Document custom commands - Help team members

Common Issues

Site Not Loading

# Restart project
ddev restart

# Check status
ddev describe

# View logs
ddev logs

# Clear Drupal cache
ddev drush cr

Database Connection Error

# Check database is running
ddev describe

# Verify settings.php or settings.ddev.php exists
ddev ssh
ls web/sites/default/settings*.php

Port Conflicts

# Stop all DDEV projects
ddev poweroff

# Check for port conflicts
lsof -i :80 -i :443

# Change router HTTP port if needed
ddev config --router-http-port=8080 --router-https-port=8443

Slow Performance on macOS

# Enable mutagen
ddev config --performance-mode=mutagen
ddev restart

# Or use NFS
ddev config --nfs-mount-enabled=true
ddev restart

PHP Deprecation Warnings in Drush

If you're seeing PHP deprecation warnings when running Drush commands (especially with PHP 8.4), create a custom PHP configuration file to suppress them:

.ddev/php/drush.ini:

; Suppress PHP deprecation warnings for Drush commands
[PHP]
error_reporting = 22527
display_errors = Off
display_startup_errors = Off
log_errors = On
error_log = /tmp/php-errors.log

Then restart DDEV:

ddev restart

How it works:

• error_reporting = 22527 equals E_ALL & ~E_DEPRECATED
• display_errors = Off prevents warnings from appearing on STDERR
• display_startup_errors = Off suppresses bootstrap warnings
• Errors are logged to /tmp/php-errors.log instead of being displayed

This configuration applies to both web and CLI contexts since DDEV copies .ddev/php/*.ini files to both /etc/php/[version]/cli/conf.d/ and /etc/php/[version]/fpm/conf.d/.

Interrupted ddev composer install Leaves Phantom-Installed Packages (Patches Never Applied)

If ddev composer install/update is killed mid-run (Docker OOM exit 137, host timeout, crash), Composer may have already recorded the package as installed before the kill — so the NEXT composer install reports "Nothing to install, update or remove" and composer-patches never applies that package's patches. The result is a half-materialized contrib tree that produces impossible-looking runtime errors (e.g. DI ServiceCircularReferenceExceptions, TypeErrors from an unpatched constructor) that do NOT reproduce once the tree is repaired.

Diagnose:

# Verify patch application (a verify-patches script if your project has one,
# or spot-check a known-patched file in the vendored tree)
ddev composer install                # says "Nothing to install" despite the missing patches

Fix — force a clean reinstall of the affected package (re-applies its patches):

ddev composer reinstall drupal/<pkg>

Rule: after ANY interrupted composer run, treat the whole package tree as suspect. Reinstall the packages that were mid-flight, re-verify patches, and only THEN debug remaining errors — the error you saw during the broken window may already be gone. Check error-log timestamps: confirm a fatal reproduces NOW before engineering a fix for it.

Timeout-Killed ddev drush Commands Orphan In-Container Processes

Killing the host-side ddev drush ... process (Ctrl-C, tool timeout) does NOT kill the php process inside the web container. Orphans accumulate, contend for CPU, and make every subsequent drush bootstrap crawl (10+ minutes for drush cr/updb/updatedb:status — looks like a hang, is actually starvation).

Diagnose / clean up:

ddev exec "ps aux | grep -v grep | grep -E 'vendor/bin/drush|php /var/www'"
ddev exec "pkill -f 'vendor/bin/drush'"

Two corollaries:

1. Run long drush operations (updb on a big upgrade, cold cr) ONCE, in the background, with a generous timeout — do not fire repeated shorter attempts; each kill adds another orphan.
2. A "hung then killed" updb may have already completed its real work — update hooks are recorded per-hook. Before re-running or panicking, check what actually executed:

ddev mysql -e "SELECT value FROM key_value WHERE collection='system.schema' AND name='<module>'"
ddev mysql -N -e "SELECT value FROM key_value WHERE collection='post_update' AND name='existing_updates'" | grep -o "<module>_post_update_[a-z0-9_]*"

Docker Engine Wedge (Check Before Iterating on DDEV)

phpunit exits 137, background jobs die mid-run, ddev exec re-triggers full image rebuilds, or every ddev start hits "container name already in use" — looks like a DDEV problem but is often the Docker Desktop engine crashed underneath still-resident app processes. Check this FIRST:

timeout 5 docker version   # hangs on the Server section -> engine is dead
docker ps                  # if this responds while `docker version` hangs, engine is wedged

Fix: killall -9 com.docker.backend && open -a Docker, poll docker ps until it responds, then ddev start. Don't keep iterating on ddev-level fixes (poweroff/mutagen reset/etc.) while the engine itself is down — none of them can succeed. After the restart, watch for orphan containers and a slow first drush: post-crash traps.

Host CPU Saturation (Containers Healthy, Requests Hang)

Host load well above core count; containers healthy and php -v instant, but every request and drush bootstrap hangs (php-fpm workers blocked in request_wait_answer on a stalled virtiofs bridge). No DDEV recovery fixes it until load drops — shed load, then one ddev poweroff && ddev start. Details: load-and-recovery.md.

Post-Recovery 404s With Route-Discovery Warnings

A 404 with route-discovery warnings right after a recovery (Docker restart, mutagen reset, core update) that ddev drush cr does not fix is usually an APCu-stale compiled container: php-fpm's opcode cache still holds pre-change code even though cache_container in the DB is fresh. Fix: docker restart ddev-<project>-web (forces fresh APCu) — not another cache clear.

Router TLS Reset While Containers Report Healthy

curl to https://<project>.ddev.site fails instantly with exit 35 ("Connection reset by peer" during TLS handshake) even though ddev describe shows everything OK and docker ps says ddev-router is healthy. The app is fine — the router is wedged.

Discriminate app vs router (bypasses the router entirely):

ddev exec "curl -s -o /dev/null -w '%{http_code}' http://localhost/<path>"

Fix:

docker restart ddev-router

Docker Desktop overlay2 I/O Errors

If Docker Desktop gets into a bad state producing overlay2 or containerd I/O errors such as:

Error response from daemon: error creating temporary lease: write /var/lib/desktop-containerd/daemon/io.containerd.metadata.v1.bolt/meta.db: input/output error

Error response from daemon: open /var/lib/docker/overlay2/...: input/output error

A normal quit and restart of Docker Desktop is not sufficient. You must force quit ALL Docker processes (via Activity Monitor or killall -9 Docker / killall -9 com.docker.hyperkit), then relaunch Docker Desktop. Only a full force quit clears the corrupted state.

"readdirent bad message" variant: signals VM-disk corruption at the container-metadata level, not a transient overlay2 hiccup — repeated ddev start will not fix it. Quarantine the corrupted container's metadata directory instead of looping restarts (enter an alpine container via nsenter and mv the offending /var/lib/docker/containers/<id> dir aside).

Unhealthy Containers / Mutagen Sync Hanging

After Docker crashes or force-quits, DDEV can get into a bad state where:

• ddev start hangs at "Starting Mutagen sync process..."
• Web container reports unhealthy (phpstatus:FAILED, mailpit:FAILED)
• ddev mutagen reset fails with "CreateOrResumeMutagenSync Failure"

Fix (run in order):

# 1. Full power off to clean up all containers and networks
ddev poweroff

# 2. Start fresh
ddev start

If ddev poweroff doesn't resolve it:

# 1. Stop DDEV
ddev stop

# 2. Reset the Mutagen daemon
~/.ddev/bin/mutagen daemon stop
~/.ddev/bin/mutagen daemon start

# 3. Reset Mutagen sync (removes Docker volume, forces full resync)
ddev mutagen reset

# 4. Start fresh
ddev start

Monitoring commands while troubleshooting:

ddev mutagen status -l      # Detailed sync status
ddev mutagen monitor        # Real-time sync progress
docker inspect --format "{{ json .State.Health }}" ddev-<project>-web  # Container health

Disk Usage: Don't Trust ls or du

ls -la reports the logical size of sparse files (e.g. Docker.raw), which can be far larger than what's actually consumed on disk; du over-reports on APFS because it double-counts copy-on-write clones shared between snapshots. Neither answers "how much space would this operation actually cost/free." Trust only df deltas taken immediately before and after the operation.

Related Skills

• @drupal-config-mgmt - Config management workflows
• @drupal-contrib-mgmt - Module management with Composer
• @drupal-at-your-fingertips - General Drupal patterns

Official Documentation: https://ddev.readthedocs.io Drupal DDEV Quickstart: https://ddev.readthedocs.io/en/stable/users/quickstart/ Community Support: https://discord.gg/5wjP76mBJD