Add preference for HostCPUFeatures so that it can be loaded/used

Author: gbaraldi

src/compiling.jl

@@ -78,7 +78,29 @@ function compile_products(recipe::ImageRecipe)
     end
 
     project_arg = recipe.project == "" ? Base.active_project() : recipe.project
-    env_overrides = Dict{String,Any}("JULIA_LOAD_PATH"=>nothing)
+    env_overrides = Dict{String,Any}()
+    tmp_prefs_env = nothing
+    if is_trim_enabled(recipe)
+        # Create a temporary depot so packages are recompiled fresh with the trim preference
+        load_path_sep = Sys.iswindows() ? ";" : ":"
+        
+        # Create a temporary environment with a LocalPreferences.toml that will be added to JULIA_LOAD_PATH. 
+        tmp_prefs_env = mktempdir()
+        # env_overrides["JULIA_DEPOT_PATH"] = tmp_prefs_env * load_path_sep
+        open(joinpath(tmp_prefs_env, "Project.toml"), "w") do io
+            println(io, "[deps]")
+            println(io, "HostCPUFeatures = \"3e5b6fbb-0976-4d2c-9146-d79de83f2fb0\"")
+        end
+        # Write LocalPreferences.toml with the trim preferences
+        open(joinpath(tmp_prefs_env, "LocalPreferences.toml"), "w") do io
+            println(io, "[HostCPUFeatures]")
+            println(io, "freeze_cpu_target = true")
+        end
+        # Prepend the temp env to JULIA_LOAD_PATH
+
+        env_overrides["JULIA_LOAD_PATH"] = load_path_sep * tmp_prefs_env 
+    end
+
     inst_cmd = addenv(`$(Base.julia_cmd(cpu_target=precompile_cpu_target)) --project=$project_arg -e "using Pkg; Pkg.instantiate(); Pkg.precompile()"`, env_overrides...)
     recipe.verbose && println("Running: $inst_cmd")
     precompile_time = time_ns()

test/TrimmabilityProject/Project.toml

@@ -3,4 +3,8 @@ uuid = "a1b2c3d4-5678-90ab-cdef-1234567890ab"
 version = "0.1.0"
 
 [deps]
+HostCPUFeatures = "3e5b6fbb-0976-4d2c-9146-d79de83f2fb0"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
+
+[compat]
+HostCPUFeatures = "0.1.18"

test/TrimmabilityProject/src/TrimmabilityProject.jl

@@ -1,6 +1,7 @@
 # Test that various constructs support trimming
 module TrimmabilityProject
 
+using HostCPUFeatures
 using Sockets
 
 world::String = "world!"