Auto merge of #5763 - ehuss:pkg-modify-mac, r=alexcrichton

Fix flakey test on MacOS.

`do_not_package_if_src_was_modified` can fail if the test runs too quickly
due to mac's filesystem time resolution.

Author: bors

tests/testsuite/package.rs

@@ -4,7 +4,7 @@ use std::io::prelude::*;
 use std::path::{Path, PathBuf};
 
 use git2;
-use cargotest::{cargo_process, process, ChannelChanger};
+use cargotest::{cargo_process, process, sleep_ms, ChannelChanger};
 use cargotest::support::{cargo_exe, execs, git, paths, project, registry, path2url};
 use cargotest::support::registry::Package;
 use flate2::read::GzDecoder;
@@ -1440,6 +1440,13 @@ fn do_not_package_if_src_was_modified() {
         "#)
         .build();
 
+    if cfg!(target_os = "macos") {
+        // MacOS has 1s resolution filesystem.
+        // If src/main.rs is created within 1s of src/generated.txt, then it
+        // won't trigger the modification check.
+        sleep_ms(1000);
+    }
+
     assert_that(
         p.cargo("package"),
         execs().with_status(101)