Fix activating [sources] with relative paths

src/julia-1.11/activate_set.jl

@@ -54,6 +54,18 @@ function activate(pkg::AbstractString=current_pkg_name(); allow_reresolve=true)
     temp_ctx = Context()
     temp_ctx.env.project.deps[pkgspec.name] = pkgspec.uuid
 
+    # A hack to get [sources] with relative paths working. We just dive into the project
+    # context and replace all the relative '{path = ".."}' instances with the corresponding
+    # absolute paths. `pkgspec.path` is assumed to be relative to the Project.toml file
+    # that we are activating and has the relative paths.
+    for source in values(temp_ctx.env.project.sources)
+        isa(source, Dict) || continue
+        haskey(source, "path") || continue
+        if !isabspath(source["path"])
+            source["path"] = joinpath(pkgspec.path, source["path"])
+        end
+    end
+
     try
         Pkg.resolve(temp_ctx; io=devnull)
         @debug "Using _parent_ dep graph"

test/activate_set.jl

@@ -86,4 +86,24 @@
             @test isdefined(TestEnv, :isfixed)
         end
     end
+
+    if VERSION >= v"1.11"
+        @testset "activate with [sources]" begin
+            orig_project_toml_path = Base.active_project()
+            push!(LOAD_PATH, mktempdir())  # put something weird in LOAD_PATH for testing
+            orig_load_path = Base.LOAD_PATH
+            try
+                Pkg.activate(joinpath(@__DIR__, "sources", "MainEnv"))
+                TestEnv.activate()
+                new_project_toml_path = Base.active_project()
+                @test new_project_toml_path != orig_project_toml_path
+                @test orig_load_path == Base.LOAD_PATH
+                @eval using MainEnv
+                @test isdefined(@__MODULE__, :MainEnv)
+                @test MainEnv.bar() == 42
+            finally
+                Pkg.activate(orig_project_toml_path)
+            end
+        end
+    end
 end

test/sources/DependentEnv/Project.toml

@@ -0,0 +1,12 @@
+name = "DependentEnv"
+uuid = "c9261501-a1a4-4a21-a37c-0c7025a0fef8"
+version = "0.0.0"
+
+[deps]
+JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
+
+[extras]
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Test"]

test/sources/DependentEnv/src/DependentEnv.jl

@@ -0,0 +1,6 @@
+module DependentEnv
+using JSON
+
+foo() = 40
+
+end

test/sources/MainEnv/Project.toml

@@ -0,0 +1,16 @@
+name = "MainEnv"
+uuid = "1b324c26-e66a-4bf4-9aeb-d8ecf06e8e93"
+version = "0.0.0"
+
+[deps]
+DependentEnv = "c9261501-a1a4-4a21-a37c-0c7025a0fef8"
+TOML = "fa267f1f-6049-4f14-aa54-33bafae1ed76"
+
+[sources]
+DependentEnv = {path = "../DependentEnv"}
+
+[extras]
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Test"]

test/sources/MainEnv/src/MainEnv.jl

@@ -0,0 +1,6 @@
+module MainEnv
+using DependentEnv
+
+bar() = DependentEnv.foo() + 2
+
+end

test/sources/MainEnv/test/runtests.jl

@@ -0,0 +1,4 @@
+using MainEnv
+using Test
+
+@test MainEnv.bar() == 42