PkgEval.jl

Evaluate Julia packages.

PkgEval.jl is a package to test one or more Julia versions against the Julia package ecosystem, and is used by Nanosoldier.jl for keeping track of package compatibility of upcoming Julia versions.

Note that for now, PkgEval.jl is Linux-only, and even requires a sufficiently recent kernel (at least 5.11, or a distribution like Ubuntu that has back-ported support for unprivileged overlayfs mounts in user namespaces).

Quick start

PkgEval is not a registered package, so you'll need to install it from Git:

git clone https://github.com/JuliaCI/PkgEval.jl.git
cd PkgEval.jl
julia --project -e 'import Pkg; Pkg.instantiate()'

To quickly test a package, a script has been provided under the bin/ folder:

$ julia --project bin/test_package.jl --name=Example
Package evaluation of Example started at 2022-11-27T09:30:27.777
...
Testing completed after 1.04s

This script can also be used to test specific versions of a package by setting any of the --version, --rev, or --url arguments. To test a version of a package you only have locally, e.g., a development version, use the --path argument instead:

$ julia --project bin/test_package.jl --name Example --path=~/.julia/dev/Example

By default, this will use the latest nightly version of Julia, which is what PkgEval uses. To use another version, use the --julia argument, e.g., --julia=1.8.

API

To use PkgEval programmatically, there are three main interfaces do deal with:

• Configuration objects to determine how to execute tests (which Julia version, build flags, any environment variables, ...)
• Package objects to select packages to test
• the evaluate function to evaluate every package on each provieded configuration, returning the results in a DataFrame

julia> using PkgEval

julia> config = Configuration(; julia="1.7");

julia> package = Package(; name="Example");

julia> evaluate([config], [package])
1×9 DataFrame
 Row │ julia_spec  julia_version  compiled  name     version    ⋯
     │ String      VersionNumber  Bool      String   VersionN…? ⋯
─────┼───────────────────────────────────────────────────────────
   1 │ 1.7         1.7.0             false  Example  0.5.3      ⋯
                                                4 columns omitted

Test logs are part of this dataframe in the log column. For example, in this case:

Resolving package versions...
Installed Example ─ v0.5.3
...
Testing Example tests passed

Why does my package fail?

If you want to debug why your package fails, it's probably easiest to use an interactive shell:

julia> using PkgEval

julia> config = Configuration()
PkgEval configuration(
  ...
)

julia> PkgEval.sandboxed_julia(config)

   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.9.0-DEV.1163 (2022-08-21)
 _/ |\__'_|_|_|\__'_|  |  Commit 696f7d3dfe1 (1 day old master)
|__/                   |

julia> # we're in the PkgEval sandbox here

Now you can install, load and test your package. This will, by default, use a nightly build of Julia. If you want PkgEval.jl to compile Julia, e.g. to test a specific version, create a Configuration instance as such:

julia> config = Configuration(julia="master",
                              buildflags=["JULIA_CPU_TARGET=native", "JULIA_PRECOMPILE=0"])

# NOTE: buildflags are specified to speed-up the build

Resource constraints

PkgEval uses cgroups for restricting the resources each package can use. By default however, non-root users can control the memory and pids cgroup controllers. To enable PkgEval to control more resources, run the following commands:

$ sudo mkdir -p /etc/systemd/system/user@.service.d
$ cat <<EOF | sudo tee /etc/systemd/system/user@.service.d/delegate.conf
[Service]
Delegate=cpu cpuset io memory pids
EOF
$ sudo systemctl daemon-reload

In addition, some container runtimes (i.e. runc) want full control over the current cgroup, which can be done by launching Julia as a scoped service:

systemd-run --user --scope -p Delegate=yes julia ...