Modules' __init__ should be called in imported order

[tkf]

Currently, compile_incremental(:PyCall) generates incremental_precompile.jl containing something like

using Pkg, Statistics, Test, Libdl, Conda, Serialization, LinearAlgebra,
    PyCall, VersionParsing, MacroTools, Dates, PackageCompiler
for Mod in [Pkg, Statistics, Test, Libdl, Conda, Serialization, LinearAlgebra,
    PyCall, VersionParsing, MacroTools, Dates, PackageCompiler]
    isdefined(Mod, :__init__) && Mod.__init__()
end

PyCall depends on MacroTools (Conda, and VersionParsing). Furthermore, in principle, PyCall's top-level code and macros can depend on the global state configured in MacroTools.__init__ (PyCall does not depend on it ATM. However, you can check it by adding, e.g., println(MacroTools.@expand @time foo()) in PyCall.__init__). So, shouldn't using MacroTools and MacroTools.__init__() come before using PyCall? That is to say, I think incremental_precompile.jl needs to contain something like

for name in [...,
            :MacroTools,
            :VersionParsing,
            :Conda,
            :PyCall,
            ...]
    Core.eval(@__MODULE__, :(using $name))
    Mod = Core.eval(@__MODULE__, name)
    isdefined(Mod, :__init__) && Mod.__init__()
end

In general, I think the packages have to be imported and __init__'ed in the topologically sorted order. Or maybe it is better be fixed in Julia side? JuliaLang/julia#22910

[tkf]

You can find a function that does this here: https://github.com/tkf/julia-sysimage-recipes/blob/master/lib/moduleloader.jl

[KristofferC]

Why are __init__s getting called explicitly at all?

[tkf]

Please see #277 (comment)