Error while using coroutines

[thegreathir]

I'm using v1.0.2, this is my code:

#include "kj/async-io.h"

kj::Promise<void> loop(kj::AsyncIoContext &io) {
  auto addr = co_await io.provider->getNetwork().parseAddress("", 12);
  auto receiver = addr->listen();
  auto conn = co_await receiver->accept();
  co_return;
}

int main() {
  auto io = kj::setupAsyncIo();
  loop(io).wait(io.waitScope);
  return 0;
}

This is how I compile it:

set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -freport-bug -fcoroutines")
add_executable(
    main main.cpp
)

set_property(TARGET main PROPERTY CXX_STANDARD 20)
target_link_libraries(main kj)

Am I doing something obviously wrong?
Because compiler crashes:

main.cpp:8:1: internal compiler error: in gimplify_var_or_parm_decl, at gimplify.cc:3058
    8 | }
      | ^
0x1ad33c8 internal_error(char const*, ...)
	???:0
0x6b7b63 fancy_abort(char const*, int, char const*)
	???:0
0xb96497 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb96546 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb96a34 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb965ff gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb97cbf gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb96fc5 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb97c5f gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb96fc5 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb96326 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb96fc5 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb97c5f gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int)
	???:0
0xb9938b gimplify_body(tree_node*, bool)
	???:0
0xb998d0 gimplify_function_tree(tree_node*)
	???:0
0x9f824b cgraph_node::analyze()
	???:0
0xa01796 symbol_table::finalize_compilation_unit()
	???:0
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://bugs.archlinux.org/> for instructions.

I'm going to report it to GCC btw.

[kentonv]

This is a known GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102051

KJ coroutines simply don't work on GCC until this is fixed. Sorry. They work great in Clang.