Can't precompile package (LoadError: could not open file)

[efaulhaber]

For a simple testing action, I tried using the following workflow:

name: CI

on: push

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Check out project
        uses: actions/checkout@v2
      - name: Set up Julia
        uses: julia-actions/setup-julia@v1
        with:
          version: '1.5.2'
      - name: Build package
        uses: julia-actions/julia-buildpkg@v1
      - name: Run tests
        uses: julia-actions/julia-runtest@v1

This workflow fails with

  [2f01184e] SparseArrays
  [10745b16] Statistics
  [8dfed614] Test
  [cf7118a7] UUIDs
  [4ec0a83e] Unicode
ERROR: LoadError: could not open file /home/runner/work/Numerik4/Numerik4/src/interpolation/interpolation.jl
Stacktrace:
 [1] include(::Function, ::Module, ::String) at ./Base.jl:380
 [2] include at ./Base.jl:368 [inlined]
 [3] include(::String) at /home/runner/work/Numerik4/Numerik4/src/Numerik4.jl:1
 [4] top-level scope at /home/runner/work/Numerik4/Numerik4/src/Numerik4.jl:13
 [5] include(::Function, ::Module, ::String) at ./Base.jl:380
 [6] include(::Module, ::String) at ./Base.jl:368
 [7] top-level scope at none:2
 [8] eval at ./boot.jl:331 [inlined]
 [9] eval(::Expr) at ./client.jl:467
 [10] top-level scope at ./none:3
in expression starting at /home/runner/work/Numerik4/Numerik4/src/Numerik4.jl:13
ERROR: LoadError: Failed to precompile Numerik4 [f3a1b8d1-e5d1-4887-8cc0-bff5bbf1cb5d] to /home/runner/.julia/compiled/v1.5/Numerik4/pjzXq_ymcLB.ji.
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] compilecache(::Base.PkgId, ::String) at ./loading.jl:1305
 [3] _require(::Base.PkgId) at ./loading.jl:1030
 [4] require(::Base.PkgId) at ./loading.jl:928
 [5] require(::Module, ::Symbol) at ./loading.jl:923
 [6] include(::String) at ./client.jl:457
 [7] top-level scope at none:6
in expression starting at /home/runner/work/Numerik4/Numerik4/test/runtests.jl:2
ERROR: Package Numerik4 errored during testing
Stacktrace:
 [1] pkgerror(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/Types.jl:52
 [2] test(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}; coverage::Bool, julia_args::Cmd, test_args::Cmd, test_fn::Nothing) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/Operations.jl:1578
 [3] test(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}; coverage::Bool, test_fn::Nothing, julia_args::Cmd, test_args::Cmd, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/API.jl:327
 [4] #test#61 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/API.jl:67 [inlined]
 [5] test(; name::Nothing, uuid::Nothing, version::Nothing, url::Nothing, rev::Nothing, path::Nothing, mode::Pkg.Types.PackageMode, subdir::Nothing, kwargs::Base.Iterators.Pairs{Symbol,Bool,Tuple{Symbol},NamedTuple{(:coverage,),Tuple{Bool}}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/API.jl:80
 [6] top-level scope at none:1

Line 2 in runtests.jl is just using Numerik4.
Line 13 in Numerik4.jl is include("interpolation/interpolation.jl") (first line after module Numerik4 and some using lines).

I tried running the exact same lines from the source code of julia-buildpkg and julia-runtest in my ubuntu-latest VM with Julia 1.5.2 installed (that's why I'm using 1.5.2 in the workflow. It failed with 1.5.3 too). Everything works as expected there.
I also tried with julia-runtest@master.

[DilumAluthge]

In your GitHub Actions workflow file, try replacing this line...

uses: julia-actions/julia-runtest@v1

... with this line instead:

run: julia --project -e 'import Pkg; Pkg.test()'

If you do that, do you still see the error?