(@v1.9) pkg> status
Status `C:\Users\jmzhang\.julia\environments\v1.9\Project.toml`
[7d9fca2a] Arpack v0.5.4
[6e4b80f9] BenchmarkTools v1.4.0
[a93c6f00] DataFrames v1.6.1
⌃ [0c46a032] DifferentialEquations v7.11.0
[0b1a1467] KrylovKit v0.6.0
[b964fa9f] LaTeXStrings v1.3.1
[91a5bcdd] Plots v1.39.0
[27ebfcd6] Primes v0.5.5
[c46f51b8] ProfileView v1.7.2
[c53c40cc] Rimu v0.10.2
⌃ [90137ffa] StaticArrays v1.8.0
[409d34a3] VectorInterface v0.4.2
Info Packages marked with ⌃ have new versions available and may be upgradable.
julia> using LinearAlgebra
julia>
I did not see it in the pkg list, but I can use it.
Here, you are using your standard environment, which is why LinearAlgebra isn’t listed explicitly. In all other environments, LinearAlgebra or any other package in the standard library should be added like any other dependency, so it should be in your Project.toml[deps] and [compat] section.
I believe this relate only to recent - or even future - versions of Julia. The clear direction is to consider standard lib packages as “normal” packages that just happens to be shipped with Julia - so with all the requirements in terms of naming and bounding them, but there is a bit of fog related to the version of Julia this would actually apply…
You’ve always (since Julia 1.0) needed to list standard library packages in your Project.toml. It’s only recently (since Nov. 2023) that you needed to list version requirements for stdlib packages, but even then it’s only required if you want to register your package: PSA: Compat requirements in the General registry are changing