Throw an error if the current Julia version (Base.VERSION) is incompatible with the [compat] entry for julia in the Project.toml file

CHANGELOG.md

@@ -1,3 +1,12 @@
+Pkg v1.11 Release Notes
+=======================
+
+- Pkg now obeys `[compat]` bounds for `julia` and raises an error if the version of the running Julia binary is incompatible with the bounds in `Project.toml`.
+  Pkg has always obeyed this compat when working with Registry packages. This change affects mostly local packages. ([#3526])
+
+Pkg v1.10 Release Notes
+=======================
+
 Pkg v1.9 Release Notes
 =======================
 

src/Operations.jl

@@ -242,13 +242,10 @@ function collect_project(pkg::PackageSpec, path::String)
         pkgerror("could not find project file for package $(err_rep(pkg)) at `$path`")
     end
     project = read_package(project_file)
-    #=
-    # TODO, this should either error or be quiet
     julia_compat = get_compat(project, "julia")
-    if julia_compat !== nothing && !(VERSION in julia_compat)
-        println(io, "julia version requirement for package $(err_rep(pkg)) not satisfied")
+    if !isnothing(julia_compat) && !(VERSION in julia_compat)
+        pkgerror("julia version requirement from Project.toml's compat section not satisfied for package $(err_rep(pkg)) at `$path`")
     end
-    =#
     for (name, uuid) in project.deps
         vspec = get_compat(project, name)
         push!(deps, PackageSpec(name, uuid, vspec))

test/api.jl

@@ -392,4 +392,13 @@ end
     end
 end
 
+@testset "`[compat]` entries for `julia`" begin
+    isolate(loaded_depot=true) do; mktempdir() do tempdir
+        pathf = git_init_package(tempdir, joinpath(@__DIR__, "test_packages", "FarFuture"))
+        pathp = git_init_package(tempdir, joinpath(@__DIR__, "test_packages", "FarPast"))
+        @test_throws "julia version requirement from Project.toml's compat section not satisfied for package" Pkg.add(path=pathf)
+        @test_throws "julia version requirement from Project.toml's compat section not satisfied for package" Pkg.add(path=pathp)
+    end end
+end
+
 end # module APITests

test/test_packages/FarFuture/Project.toml

@@ -0,0 +1,7 @@
+name = "FarFuture"
+uuid = "501ba3b0-7baa-46f4-8e2b-5f7988aeacaf"
+authors = ["The Jetsons"]
+version = "0.1.0"
+
+[compat]
+julia = "1.999.0"

test/test_packages/FarFuture/src/FarFuture.jl

@@ -0,0 +1,5 @@
+module FarFuture
+
+greet() = print("Hello World!")
+
+end # module

test/test_packages/FarPast/Project.toml

@@ -0,0 +1,7 @@
+name = "FarPast"
+uuid = "501ba3b0-7baa-46f4-8e2b-5f7988aeaca0"
+authors = ["The Flintstones"]
+version = "0.1.0"
+
+[compat]
+julia = "<1.1.0"

test/test_packages/FarPast/src/FarPast.jl

@@ -0,0 +1,5 @@
+module FarPast
+
+greet() = print("Hello World!")
+
+end # module