Importing modules from inside include! no longer works

[jdm]

This code works in the 2020-03-19 nightly:

build.rs:

use std::env;
use std::fs;
use std::path::PathBuf;

fn main() {
    let out_dir = env::var("OUT_DIR").unwrap();
    let path: PathBuf = [out_dir.clone(), "foo.rs".to_string()].iter().collect();
    fs::write(path, "pub mod foo2;").unwrap();

    let path: PathBuf = [out_dir, "foo2.rs".to_string()].iter().collect();
    fs::write(path, "pub fn foo_fn() {}").unwrap();
}

lib.rs:

mod stuff {
    include!(concat!(env!("OUT_DIR"), "/foo.rs"));
}

fn main() {
    stuff::foo2::foo_fn();
}

The resulting OUT_DIR looks like:

$ ls target/debug/build/regress-d7c49d33c7449edf/out
foo.rs	foo2.rs

With the 2020-03-20 nightly, this crate generates the following output:

error[E0583]: file not found for module `foo2`
 --> /Users/joshmatthews/regress/target/debug/build/regress-1976556320d6d1b4/out/foo.rs:1:1
  |
1 | pub mod foo2;
  | ^^^^^^^^^^^^^
  |
  = help: to create the module `foo2`, create file "src/stuff/foo2.rs"

error[E0425]: cannot find function `foo_fn` in module `stuff::foo2`
 --> src/main.rs:7:18
  |
7 |     stuff::foo2::foo_fn();
  |                  ^^^^^^ not found in `stuff::foo2`

error: aborting due to 2 previous errors

I suspect either #68941 or #66131.

[SimonSapin]

Regression range: f509b26...f4c675c

Merge commits in that range:

• Auto merge of Extend search #69402 - GuillaumeGomez:extend-search, r=kinnison
• Auto merge of update miri #70137 - RalfJung:miri, r=RalfJung
• Auto merge of rustc: use LocalDefId instead of DefIndex where possible. #66131 - eddyb:local-def-id, r=petrochenkov
• Auto merge of Rollup of 9 pull requests #70132 - Centril:rollup-oe8unsn, r=Centril
• Rollup merge of Use copy bound in atomic operations to generate simpler MIR #70088 - tmiasko:atomic-copy, r=eddyb
• Rollup merge of [rustdoc] Improve visibility for code blocks warnings #70005 - GuillaumeGomez:code-block-signs, r=kinnison
• Rollup merge of unix: Set a guard page at the end of signal stacks #69969 - iximeow:sigstack-guard-page, r=cuviper
• Rollup merge of std: Don't abort process when printing panics in tests #69959 - alexcrichton:fix-panic-in-print, * r=Mark-Simulacrum
• Rollup merge of Regenerate tables for Unicode 13.0.0 #69929 - cuviper:unicode-13.0.0, r=Mark-Simulacrum
• Rollup merge of Smaller and more correct generator codegen #69814 - jonas-schievink:gen-ret-unw, r=Zoxc
• Rollup merge of tidy: Better license checks. #69443 - ehuss:tidy-license, r=skade,Mark-Simulacrum
• Rollup merge of rustc: don't resolve Instances which would produce malformed shims. #69036 - eddyb:monoshim, r=nikomatsakis
• Rollup merge of Properly handle Spans that reference imported SourceFiles #68941 - Aaron1011:fix/imported-span, r=petrochenkov
• Auto merge of Rollup of 2 pull requests #70118 - pietroalbini:rollup-pgjc90i, r=pietroalbini
• Rollup merge of ci: use python from the correct path #70116 - pietroalbini:ci-fix-windows-python-path, * r=Mark-Simulacrum
• Rollup merge of Rollup of 10 pull requests #70112 - Centril:rollup-gpi5tbq, r=Centril
• Rollup merge of Tidy: fix running rustfmt twice #70106 - ehuss:fix-tidy-fmt-twice, r=Mark-Simulacrum
• Rollup merge of Fix repr pretty display #70075 - GuillaumeGomez:fix-repr-display, * r=petrochenkov
• Rollup merge of Remove some imports to the rustc crate #69920 - Centril:hir-cleanup, r=Zoxc
• Rollup merge of Make methods declared by newtype_index macro const #69899 - ecstatic-morse:const-idx-methods, r=oli-obk
• Rollup merge of Miri error reform #69839 - RalfJung:miri-error-cleanup, r=oli-obk
• Rollup merge of Expansion-driven outline module parsing #69838 - Centril:expand-module, r=petrochenkov
• Rollup merge of Use smaller discriminants for generators #69837 - jonas-schievink:gen-discr-opt, r=tmandry
• Rollup merge of Erase regions in writeback #69189 - matthewjasper:erase-the-world, r=nikomatsakis
• Rollup merge of clean up E0308 explanation #69139 - GuillaumeGomez:cleanup-e0308, r=Dylan-DPC
• Rollup merge of keyword docs for else and inkeyword docs for else and in. #67749 - gilescope:keyword-in, r=Dylan-DPC

[jonas-schievink]

probably cause: #69838

cc @Centril

[jdm]

Looks like this should be fixed by #70184?

[Centril]

@jdm Yeah that should fix it.

[Centril]

#70184 has landed now. @jdm can you confirm on the next nightly whether the issue was fixed for y'all?

[SimonSapin]

Confirmed fixed in nightly-2020-03-22 https://community-tc.services.mozilla.com/tasks/KSO29SSUQyaUgw_WyYnkgg/runs/0/logs/live/https%3A%2F%2Fcommunity-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FKSO29SSUQyaUgw_WyYnkgg%2Fruns%2F0%2Fartifacts%2Fpublic%2Flogs%2Flive.log#L367

Thanks for the quick response!