Switch all builds from Travis to Cirrus

Travis has been super-slow lately (> 6 hours per build).  Cirrus is much
faster: about 20 minutes.  Cirrus also has slightly better test
coverage, mainly because it doesn't use SECCOMP.

Also,

* Fix the Redox CI build.  The old Travis configuration didn't actually
  build for Redox, so we never noticed that Redox can't be built with a
  stable compiler.  Thanks to @coolreader18 for finding this.

* Disable the udp_offload tests on cross-tested platforms.  These tests
  are failing with ENOPROTOOPT in Cirrus-CI.  I suspect it's due to a
  lack of support in QEMU.  These tests were skipped on Travis because
  its kernel was too old.

* Fix require_kernel_version on Cirrus-CI.  Cirrus reports the Linux
  kernel version as 4.19.112+, which the semver crate can't handle.

* Fix test_setfsuid on Cirrus.  When run on Cirrus, it seems like the
  file in /tmp gets deleted as soon as it's closed.  Probably an
  overzealous temporary file cleaner.  Use /var/tmp, because no
  temporary file cleaner should run in there.

* Skip mount tests on Cirrus.  They fail for an unknown reason.
Issue #1351

* Skip the AF_ALG tests on Cirrus-CI
Issue #1352

1 files changed, 4 insertions, 1 deletions

diff --git a/test/test_unistd.rs b/test/test_unistd.rs
index 34f7f561..de696718 100644
--- a/test/test_unistd.rs
+++ b/test/test_unistd.rs
@@ -26,6 +26,8 @@ use std::path::Path;
 use tempfile::{tempdir, tempfile};
 use libc::{_exit, off_t};
 
+use crate::*;
+
 #[test]
 #[cfg(not(any(target_os = "netbsd")))]
 fn test_fork_and_waitpid() {
@@ -990,8 +992,9 @@ fn test_setfsuid() {
     let nobody = User::from_name("nobody").unwrap().unwrap();
 
     // create a temporary file with permissions '-rw-r-----'
-    let file = tempfile::NamedTempFile::new().unwrap();
+    let file = tempfile::NamedTempFile::new_in("/var/tmp").unwrap();
     let temp_path = file.into_temp_path();
+    dbg!(&temp_path);
     let temp_path_2 = (&temp_path).to_path_buf();
     let mut permissions = fs::metadata(&temp_path).unwrap().permissions();
     permissions.set_mode(640);