Building Servo
If this is your first time building Servo, be sure to set up your environment before continuing with the steps below.
To build servoshell for your machine:
$ ./mach build -d
To build servoshell for Android (armv7):
$ ./mach build --android
To check your code for compile errors, without a full build:
$ ./mach check
Sometimes the tools or dependencies needed to build Servo will change.
If you start encountering build problems after updating Servo, try running ./mach bootstrap again, or set up your environment from the beginning.
You are not alone! If you have problems building Servo that you can’t solve, you can always ask for help in the build issues chat on Zulip.
Build profiles
There are three main build profiles, which you can build and use independently of one another:
- debug builds, which allow you to use a debugger (lldb)
- release builds, which are slower to build but more performant
- production builds, which are used for official releases only
| debug | release | production | |
|---|---|---|---|
| mach option | -d
| -r
| --prod
|
| optimised? | no | yes | yes, more than in release |
| maximum RUST_LOG level | trace
| info
| info
|
| debug assertions? | yes | yes(!) | no |
| debug info? | yes | no | no |
| symbols? | yes | no | yes |
| finds resources in current working dir? | yes | yes | no(!) |
There are also two special variants of production builds for performance-related use cases:
production-strippedbuilds are ideal for benchmarking Servo over time, with debug symbols stripped for faster initial startupprofilingbuilds are ideal for profiling and troubleshooting performance issues; they behave like a debug or release build, but have the same performance as a production build
| production | production-stripped | profiling | |
|---|---|---|---|
mach --profile
| production
| production-stripped
| profiling
|
| debug info? | no | no | yes |
| symbols? | yes | no | yes |
| finds resources in current working dir? | no | no | yes(!) |
You can change these settings in a servobuild file (see servobuild.example) or in the root Cargo.toml.
Optional build settings
Some build settings can only be enabled manually:
- AddressSanitizer builds are enabled with
./mach build --with-asan - crown linting is recommended when hacking on DOM code, and is enabled with
./mach build --use-crown - SpiderMonkey debug builds are enabled with
./mach build --debug-mozjs, or[build] debug-mozjs = truein your servobuild file