Test: prune old LA based on ENV variable (#1335)

This PR prunes the old `LinearAlgebra` module based on an environment
variable that is set in `.ci/run_tests.jl`. Hopefully, this would mean
that tests that are being run without this environment variable would
run as expected without precompilation issues.

The goal of this PR is to ensure that when julia is being built with the
master branch of `LinearAlgebra`, the tests would work without the need
for pruning (i.e., we want to fix the test failures in
JuliaLang/julia#58242).

This would also mean that to run the tests locally, one would need to
set the `JULIA_PRUNE_OLD_LA` environment variable to `true`.

(cherry picked from commit 87d4c8b)

Author: jishnub

.ci/run_tests.jl

@@ -6,6 +6,5 @@ end
 
 proj = abspath(joinpath(@__DIR__, ".."))
 cmd = """Base.runtests(["LinearAlgebra"]; propagate_project=true, ncores=$ncores)"""
-withenv("JULIA_NUM_THREADS" => 1) do
-    run(`$(Base.julia_cmd()) --project=$proj --compiled-modules=existing -e $cmd`)
-end
+run(addenv(`$(Base.julia_cmd()) --project=$proj --compiled-modules=existing -e $cmd`,
+    "JULIA_NUM_THREADS" => 1, "JULIA_PRUNE_OLD_LA" => true))

README.md

@@ -37,10 +37,37 @@ This package performs some type piracy and is also included in the sysimage, whi
 To use a development version of this package, you can choose one of the following methods:
 
 1. **Change the UUID in the project file and load the package:**
-   This approach will produce warnings and may lead to method ambiguities between the development version and the one in the sysimage, but it can be used for basic experimentation.
+
+   Change the UUID line in `Project.toml` as
+   ```diff
+   - uuid = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+   + uuid = "27e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+   ```
+
+   Start `julia` as
+   ```console
+   JULIA_PRUNE_OLD_LA=true julia +nightly --compiled-modules=existing --project
+   ```
+   where it is assumed that one is already within the `LinearAlgebra` directory (otherwise, adjust
+   the project path accordingly). The `julia +nightly` command above assumes that `juliaup` is being used
+   to launch `julia`, but one may substitute this with the path to the julia executable.
+
+   Within the `julia` session, load the `LinearAlgebra` module after pruning the one in the sysimage. This may be done as
+   ```julia
+   include("test/prune_old_LA.jl") && using LinearAlgebra
+   ```
+
+   Note that loading the test files in the REPL will automatically carry out the pruning to ensure that the development version of the package is used in the tests.
+
+   If you are contributing to the repo using this method, it may be convenient to ignore the local changes to `Project.toml` by running
+   ```console
+   git update-index --skip-worktree Project.toml
+   ```
 
 2. **Build Julia with the custom `LinearAlgebra` commit:**
-   Modify the commit in `stdlib/LinearAlgebra.version` and build Julia.
+
+   Modify the commit in [`stdlib/LinearAlgebra.version`](https://github.com/JuliaLang/julia/blob/master/stdlib/LinearAlgebra.version) and build Julia. This requires one to push the development branch
+   to `GitHub` or an equivalent platform.
 
 3. **Build a custom sysimage with the new `LinearAlgebra`:**
    - Install `PackageCompiler`.

docs/make.jl

@@ -1,4 +1,6 @@
-include("../test/prune_old_LA.jl")
+withenv("JULIA_PRUNE_OLD_LA" => "true") do
+    include("../test/prune_old_LA.jl")
+end
 
 using LinearAlgebra
 using Documenter: DocMeta, makedocs, deploydocs, HTML

test/bitarray.jl

@@ -1,3 +1,7 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+module TestBitArray
+
 isdefined(Main, :pruned_old_LA) || @eval Main include("prune_old_LA.jl")
 
 using LinearAlgebra, Test, Random
@@ -95,3 +99,5 @@ b2 = bitrand(v1)
 
 b1 = bitrand(n1, n1)
 @check_bit_operation diag(b1)
+
+end # module

test/prune_old_LA.jl

@@ -1,56 +1,58 @@
-methods_to_delete =
-[
-:adjoint
-:transpose
-:inv
-:literal_pow
-:\
-:/
-:isapprox
-:copyto!
-:*
-:muladd
-:copyto!
-:isone
-:kron!
-:kron
-:^
-:exp
-:cis
-:log
-:sqrt
-:cbrt
-:inv
-:cos
-:sin
-:sincos
-:tan
-:cosh
-:sinh
-:tanh
-:acos
-:asin
-:atan
-:acosh
-:asinh
-:atanh
-:sec
-:sech
-:csc
-:csch
-:cot
-:coth
-:asec
-:asech
-:acsc
-:acot
-:acoth
-:acsch
-]
-
 let
-    LA = get(Base.loaded_modules, Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra"), nothing)
-    if LA !== nothing
+    methods_to_delete =
+    [
+    :adjoint
+    :transpose
+    :inv
+    :literal_pow
+    :\
+    :/
+    :isapprox
+    :copyto!
+    :*
+    :muladd
+    :copyto!
+    :isone
+    :kron!
+    :kron
+    :^
+    :exp
+    :cis
+    :log
+    :sqrt
+    :cbrt
+    :inv
+    :cos
+    :sin
+    :sincos
+    :tan
+    :cosh
+    :sinh
+    :tanh
+    :acos
+    :asin
+    :atan
+    :acosh
+    :asinh
+    :atanh
+    :sec
+    :sech
+    :csc
+    :csch
+    :cot
+    :coth
+    :asec
+    :asech
+    :acsc
+    :acot
+    :acoth
+    :acsch
+    ]
+
+    prune_old_LA = parse(Bool, get(ENV, "JULIA_PRUNE_OLD_LA", "false"))
+    LinalgSysImg = Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra")
+    LA = get(Base.loaded_modules, LinalgSysImg, nothing)
+    if LA !== nothing && prune_old_LA
         @assert hasmethod(*, Tuple{Matrix{Float64}, Matrix{Float64}})
         for methss in methods_to_delete
             meths = getglobal(Base, methss)
@@ -61,9 +63,17 @@ let
             end
         end
     end
-    Base.unreference_module(Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra"))
 end
 
-@assert !hasmethod(*, Tuple{Matrix{Float64}, Matrix{Float64}})
+# check in a separate block to ensure that the latest world age is used
+let
+    prune_old_LA = parse(Bool, get(ENV, "JULIA_PRUNE_OLD_LA", "false"))
+    LinalgSysImg = Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra")
+    LA = get(Base.loaded_modules, LinalgSysImg, nothing)
+    if LA !== nothing && prune_old_LA
+        @assert !hasmethod(*, Tuple{Matrix{Float64}, Matrix{Float64}})
+    end
+    prune_old_LA && Base.unreference_module(LinalgSysImg)
+end
 
 pruned_old_LA = true