LoadError for LinearAlgebra package ONLY when running tests from pkg manager

Im setting up a package called toolpath, and writing tests for it. The tests run fine with no LoadErrors if I call them manually from the REPL using an include call. They also run fine from the command line like this: julia --project runtests.jl

However, if I try to call the tests from the pkg manager I get the following:

All toolpath tests: Error During Test at /Users/jsgray/personal/toolpath/toolpath.jl/test/runtests.jl:3
  Got exception outside of a @test
  LoadError: ArgumentError: Package LinearAlgebra not found in current path:
  - Run `import Pkg; Pkg.add("LinearAlgebra")` to install the LinearAlgebra package.
    [1] require(into::Module, mod::Symbol)
      @ Base ./loading.jl:871
    [2] include(fname::String)
      @ Base.MainInclude ./client.jl:444
    [3] macro expansion
      @ ~/personal/toolpath/toolpath.jl/test/runtests.jl:9 [inlined]
    [4] macro expansion
      @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1151 [inlined]
    [5] top-level scope
      @ ~/personal/toolpath/toolpath.jl/test/runtests.jl:6
    [6] include(fname::String)
      @ Base.MainInclude ./client.jl:444
    [7] top-level scope
      @ none:6
    [8] eval
      @ ./boot.jl:360 [inlined]
    [9] exec_options(opts::Base.JLOptions)
      @ Base ./client.jl:261
   [10] _start()
      @ Base ./client.jl:485
  in expression starting at /Users/jsgray/personal/toolpath/toolpath.jl/test/test_geometry.jl:1

This is odd because LinearAlgebra is part of the standard library. So Im not sure whats up. Of course the error msg is helpful and suggests that I add the package. Just in case, I tried that. You can see its listed in the Project.toml file.

Anyone have any suggestions? Im stumped.

CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
Colors = "5ae59095-9a9b-59fe-a467-6f913c188581"
DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
GLMakie = "e9467ef8-e4e7-5192-8a1a-b1aee30e663a"
LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
TestSetExtensions = "98d24dd4-01ad-11ea-1b02-c9a08f80db04"