Building a Julia Project

What This Guide Covers #

This guide covers build environment and configuration topics specific to Julia projects. Please make sure to read our Tutorial and general build configuration guides first.

Community-Supported Warning #

Travis CI support for Julia is contributed by the community and may be removed or altered at any time. If you run into any problems, please report them in the Travis CI Julia Community Forums and cc @ararslan, @staticfloat, and @StefanKarpinski.

For general Julia support on Travis CI go to the Travis Community or Julia Lang Slack Channel in the #testing channel.

Choosing Julia versions to test against #

Julia workers on Travis CI download and install a binary of Julia. You can specify the Julia versions to test in the julia: key in your .travis.yml file. For example:

language: julia
  - nightly
  - 1.0.6
  - 1.5.2

Acceptable formats are:

  • nightly will test against the latest nightly build of Julia.
  • X will test against the latest release for that major version. (Applies only to major versions 1 and later.)
  • X.Y will test against the latest release for that minor version.
  • X.Y.Z will test against that exact version.

The oldest versions for which binaries are available is 0.3.1 for Linux, or 0.2.0 for macOS.

Coverage #

Services such as and provide summaries and analytics of the coverage of the test suite. After enabling the respective services for the repositories, the codecov and coveralls options can be used as follows, placing them at the top level of the YAML document:

codecov: true
coveralls: true

This will then upload the coverage statistics upon successful completion of the tests to the specified services.

Default Build and Test Script #

If your repository contains JuliaProject.toml or Project.toml file, and you are building on Julia v0.7 or later, the default build script will be:

using Pkg #; verbose = true) for Julia 1.1 and up

Otherwise it will use the older form:

if VERSION >= v"0.7.0-DEV.5183"
    using Pkg
Pkg.clone(pwd())"$pkgname") #"$pkgname"; verbose = true) for Julia 1.1 and up
Pkg.test("$pkgname", coverage=true)

where the package name $pkgname is the repository name, with any trailing .jl removed.

Note that the coverage=true argument only tells Pkg.test to emit coverage information about the tests it ran; it does not submit this information to any services. To submit coverage information, see the coverage section above.

There are two scripts that describe the default behavior for using Julia with Travis CI: julia.rb and julia_spec.rb.

Dependency Management #

If your Julia package has a deps/build.jl file, then"$name") will run that file to install any dependencies of the package. If you need to manually install any dependencies that are not handled by deps/build.jl, it is possible to specify a custom dependency installation command as described in the general build configuration guide.

In a rare case, you may need to clone a private repo if it is a dependency of the repo you are trying to test. To add a private repo, check out the link here: Private Dependencies. Once you have the repo added, you will need to copy it to your julia folder and then run the default build script. Check out the script below for Linux to see how that is done:

 #- ls #Optional command.  Just here to confirm the Dependency is in the folder you think it is. 
 #- pwd #Optional command. Just here so you can see where you are in the file system to make sure the path is correct below. 
 - julia --project --color=yes --check-bounds=yes -e 'using Pkg; Pkg.develop(PackageSpec(path="/home/travis/build/path_to_private_Dependency")); Pkg.instantiate()'
 - julia --project --color=yes --check-bounds=yes -e 'using Pkg; Pkg.instantiate();;'

Note: you will need to have the project.toml file in your repo for these commands above to work. This can be found in your ~/.julia/enviroments/ folder.

Build Matrix #

For Julia projects, env and julia can be given as arrays to construct a build matrix.

Environment Variable #

The version of Julia a job is using is available as:


In addition, JULIA_PROJECT is set to @., which means Julia will search through parent directories until a Project.toml or JuliaProject.toml file is found; the containing directory then is used in the home project/environment.

Example Projects #

Here’s a list of open-source Julia projects utilizing Travis CI in different ways:

Build Config Reference #

You can find more information on the build config format for Julia in our Travis CI Build Config Reference.