postcheck panic from record with a function field with function defined on its own line

[austinclem1]

Version

commit 8f7bb2d
Roc compiler version debug-8f7bb2d9

Failing Code

r : { f : U8 -> U8 }
r = {
	f = |n| n * 2
	{
		f
	}
}

main! = |_args| {
	_n = r.f(2)
	Ok({})
}

Observations

Failed with roc build command, roc check no failure

Changes that prevent the segfault:

• Remove type annotation from r
• Function f return value doesn't depend on n i.e. f = |_n| 2
• Define f field inline like so (no intermediate f definition):

{
    f: |n| n * 2
}

• Pass n argument directly to output, no arithmetic or any other operation on it, i.e. f = |n| n

Stack Trace

thread 15434 panic: postcheck invariant violated: dispatch plan reached monotype lowering without a resolution
/home/austinclem1/projects/roc/src/postcheck/common.zig:82:24: 0x621c46c in invariant__anon_308050 (mod.zig)
        std.debug.panic("postcheck invariant violated: {s}", .{message});
                       ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:17175:29: 0x621b94d in dispatchTarget (mod.zig)
            Common.invariant("dispatch plan reached monotype lowering without a resolution");
                            ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:16320:43: 0x63aec93 in lowerDispatchExprAtType (mod.zig)
        const lookup = self.dispatchTarget(plan, dispatcher_ty);
                                          ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15829:77: 0x613e9c8 in lowerExprAtType (mod.zig)
            .dispatch_call => |plan| return try self.lowerDispatchExprAtType(expr.ty, plan, ty),
                                                                            ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:21307:85: 0x61dbd48 in lowerBindingContinuation (mod.zig)
                if (args.index >= args.args.len) break :blk try self.lowerExprAtType(args.body, result_ty);
                                                                                    ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8189:53: 0x64263ac in lowerLambdaArgsAndBody (mod.zig)
        var body = try self.lowerBindingContinuation(.{ .materialized_args = .{
                                                    ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8129:56: 0x642475f in lowerLambdaTemplate__anon_299582 (mod.zig)
        const lowered = try self.lowerLambdaArgsAndBody(lambda.args, arg_tys, lambda.body, fn_data.ret);
                                                       ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8251:44: 0x6479a97 in lowerNestedLambdaTemplate__anon_326789 (mod.zig)
        return try self.lowerLambdaTemplate(lambda, fn_ty);
                                           ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8234:67: 0x6478f10 in lowerNestedFunction (mod.zig)
            .lambda => |lambda| try self.lowerNestedLambdaTemplate(lambda, fn_ty),
                                                                  ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:2910:60: 0x64772b2 in lowerNestedFnRequest (mod.zig)
        const lowered = try request.ctx.lowerNestedFunction(request.expr_id, body_fn_ty);
                                                           ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:2858:45: 0x64757c3 in lowerNestedFnFromContext (mod.zig)
        return try self.lowerNestedFnRequest(.{
                                            ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15133:65: 0x628d6c6 in restoreConstFnTemplate (mod.zig)
                return try self.builder.lowerNestedFnFromContext(&fn_ctx, checkedLambdaExprIdForConstFn(fn_view, fn_value.fn_def), template, null);
                                                                ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15115:59: 0x628c913 in restoreConstFn (mod.zig)
        const mono_fn_id = try self.restoreConstFnTemplate(fn_value, template);
                                                          ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:14942:47: 0x6481729 in restoreConstNodeAtType (mod.zig)
                return try self.restoreConstFn(store_view, fn_id, ty);
                                              ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15051:57: 0x64846fe in restoreConstRecord (mod.zig)
                .value = try self.restoreConstNodeAtType(store_view, type_view, item, field.ty),
                                                        ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:14988:72: 0x6482f0f in restoreConstData (mod.zig)
            .record => |items| .{ .record = try self.restoreConstRecord(store_view, type_view, ty, items) },
                                                                       ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:14954:47: 0x6481d88 in restoreConstNodeAtType (mod.zig)
        const data = try self.restoreConstData(store_view, type_view, value, ty);
                                              ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:14832:70: 0x628504c in restoreConstUseAtType (mod.zig)
            .stored_const => |stored| try self.restoreConstNodeAtType(store_view, self.view, stored.node, ty),
                                                                     ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:14717:82: 0x627e617 in lowerLookupExprAtType (mod.zig)
            .top_level_const => |const_use| return try self.restoreConstUseAtType(const_use, ty, try self.evidenceForUseSite(record.expr)),
                                                                                 ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15833:76: 0x613f165 in lowerExprAtType (mod.zig)
            .lookup_local => |lookup| return try self.lowerLookupExprAtType(expr.ty, lookup.resolved, ty),
                                                                           ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8562:57: 0x6145864 in lowerExprWithType (mod.zig)
                    .receiver = try self.lowerExprAtType(field.receiver, receiver_ty),
                                                        ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15864:51: 0x61401d8 in lowerExprAtType (mod.zig)
        const lowered = try self.lowerExprWithType(checked_expr, ty);
                                                  ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:13975:51: 0x63d4c87 in lowerCallAtType__anon_302798 (mod.zig)
                .callee = try self.lowerExprAtType(call.func, fn_ty),
                                                  ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:13914:40: 0x6241c6e in lowerCall__anon_309300 (mod.zig)
        return try self.lowerCallAtType(checked_ret_ty, call, null);
                                       ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8658:43: 0x623fdd1 in lowerCallExpr__anon_309280 (mod.zig)
        const lowered = try self.lowerCall(checked_ret_ty, call);
                                          ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8341:46: 0x623dd79 in lowerExpr (mod.zig)
                return try self.lowerCallExpr(expr_id, expr.ty, call);
                                             ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:23650:41: 0x61d9f72 in lowerPatternStatement (mod.zig)
        const value = try self.lowerExpr(expr);
                                        ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:23542:58: 0x61c050f in lowerStatement (mod.zig)
                break :blk try self.lowerPatternStatement(decl.pattern, decl.expr, statement.source_region);
                                                         ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:22187:75: 0x6159ca9 in lowerBlockStatements (mod.zig)
                try lowered.append(self.allocator, try self.lowerStatement(statement));
                                                                          ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:22149:52: 0x6236eab in lowerBlock__anon_303039 (mod.zig)
        const stmts = try self.lowerBlockStatements(block.statements);
                                                   ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8572:50: 0x6145ffd in lowerExprWithType (mod.zig)
            .block => |block| try self.lowerBlock(block, ty),
                                                 ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:15864:51: 0x61401d8 in lowerExprAtType (mod.zig)
        const lowered = try self.lowerExprWithType(checked_expr, ty);
                                                  ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:21307:85: 0x61dbd48 in lowerBindingContinuation (mod.zig)
                if (args.index >= args.args.len) break :blk try self.lowerExprAtType(args.body, result_ty);
                                                                                    ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8189:53: 0x64263ac in lowerLambdaArgsAndBody (mod.zig)
        var body = try self.lowerBindingContinuation(.{ .materialized_args = .{
                                                    ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8129:56: 0x642475f in lowerLambdaTemplate__anon_299582 (mod.zig)
        const lowered = try self.lowerLambdaArgsAndBody(lambda.args, arg_tys, lambda.body, fn_data.ret);
                                                       ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:8042:69: 0x60e3525 in lowerTemplateBody (mod.zig)
                    .lambda => |lambda| try self.lowerLambdaTemplate(lambda, fn_ty),
                                                                    ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:1491:55: 0x60b4933 in lowerTemplateWithMonoFor (mod.zig)
        const lowered = try body_ctx.lowerTemplateBody(template_ref, template, body_fn_ty);
                                                      ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:3006:50: 0x60b126a in drainSpecRequestsFrom (mod.zig)
            _ = try self.lowerTemplateWithMonoFor(
                                                 ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:2984:39: 0x60b0bc5 in drainSpecRequests (mod.zig)
        try self.drainSpecRequestsFrom(graph, 0);
                                      ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:1493:35: 0x60b4af5 in lowerTemplateWithMonoFor (mod.zig)
        try self.drainSpecRequests(graph);
                                  ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:1264:49: 0x63a77aa in lowerTemplateWithMono (mod.zig)
        return try self.lowerTemplateWithMonoFor(template_ref, source_fn_ty, source_fn_key, fn_ty, evidence, null, null, null, null);
                                                ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:1253:46: 0x64eec76 in lowerTemplate (mod.zig)
        return try self.lowerTemplateWithMono(template_ref, source_fn_ty, source_ty_view.types.rootKey(source_fn_ty), fn_ty, &.{});
                                             ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:933:35: 0x64dc779 in lowerRoot (mod.zig)
            try self.lowerTemplate(template, moduleView(self.root_view), request.checked_type)
                                  ^
/home/austinclem1/projects/roc/src/postcheck/monotype/lower.zig:102:30: 0x5fa1b9a in run (mod.zig)
        try builder.lowerRoot(request);
                             ^
/home/austinclem1/projects/roc/src/lir/checked_pipeline.zig:210:48: 0x594a033 in lowerCheckedModulesToLir (mod.zig)
    var mono = try postcheck.Monotype.Lower.run(
                                               ^
/home/austinclem1/projects/roc/src/cli/main.zig:8244:67: 0x861786d in rocBuildLlvm (main.zig)
    var lowered = try lir.CheckedPipeline.lowerCheckedModulesToLir(
                                                                  ^
/home/austinclem1/projects/roc/src/cli/main.zig:6784:42: 0x9da6b12 in rocBuildDefaultApp (main.zig)
        .size, .speed => try rocBuildLlvm(ctx, synthetic_args),
                                         ^
/home/austinclem1/projects/roc/src/cli/main.zig:6729:34: 0x8613810 in rocBuild (main.zig)
        return rocBuildDefaultApp(ctx, args, source);
                                 ^
/home/austinclem1/projects/roc/src/cli/main.zig:1119:40: 0x4cf0763 in mainArgs (main.zig)
        .build => |build_args| rocBuild(&ctx, build_args, args[0]) catch |err| switch (err) {
                                       ^
/home/austinclem1/projects/roc/src/cli/main.zig:976:13: 0x4cee592 in main (main.zig)
    mainArgs(gpa, arena, args, init.io) catch |err| {
            ^