Why can't we detect at compile time module ctor/dtor cycles (instead of runtime) ?

See example below.

It should be easy to detect the chain at CT:

algo:

build graph from import dependencies a=>b if module a imports module b.

mark as red the modules that have a ctor

collapse each non-red node into its parent (and update parent's edges)

detect cycles (eg BFS)

(same with dtor)

----

a1:

import a2;

void main(){}

static this(){}

a2:

import a3;

static this(){}

a3:

import a1;

----

rdmd --force --build-only -oftest a1 #works

./test #error:

object.Exception@src/rt/minfo.d(243): Aborting: Cycle detected between modules with ctors/dtors:

a1 -> a2 -> a3 -> a1